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1993-07-16
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GALer - copyright by Christian Habermann
Asamstr. 17
85356 Freising
Germany
FidoNet: 2:246/105.10
GALer is a GAL programming device with relevant driver software. GALer is
SHAREWARE. If you use this program and/or the hardware, please
send me 20 DM or 15 US $. The circuit diagram for the hardware will
be sent to you on receipt of the shareware donation.
Send money by postal money order or cash, no checks please! If you send
me a disk you will be sent the next update of GALer when it becomes
available.
The distribution of GALer on PD-disks or through the networks is
permitted, as long as no profit is made from it, and that the included
files remain unaltered, and are distributed in their entirety. If you build
the GAL-prommer you are allowed to sell this one, to the price of the parts.
It is not allowed to sell this product in commercial way. The circuit
diagram must only be distributed privately and free of charge.
WARNING!!! The "GALer" and "GALerTest" programs send data over your Amiga's
parallel port. This means: when you have a printer, digitizer, or
something else attached, it should be switched off or disconnected, since
it is possible that you may damage them.
I CANNOT BE HELD RESPONSIBLE FOR ANY DAMAGE TO YOUR COMPUTER OR PRERIPHERALS.
The "GALer" hardware and software has been running faultlessly on my A3000.
I have tested GALer on A1000, A3000 and A4000 machines. It should run on
all other Amigas too.
The circuit diagram is 100% fault free. With careful construction
there is no reason for anything going awry. Even so the construction should
be carried out by electronics freak (you should at least have soldering
experience, and be able to intelligently read circuit diagrams). More
information about the construction can be found in chapter III.
Note: This manual sparely covers the operational theory of GAL programming.
It is not a substitute for further reading (see the end of this file for
litarature).
If you already have long experience with digital circuitry, and really don't
care how a GAL is made, or how it works internally, then this manual together
with the examples should suffice to intelligently implement your GALs.
Versions:
V1.0: Test version
V1.1: Intuition-interface added
V1.2: cured a few bugs
V1.3: cured some bugs in the GAL assembler. /name.E is no longer allowed.
The pin names of the last assembled files can be assigned to the
indicated GAL.
V1.4: Kick 2.0
new Intuition environment
support of A- and B-type GALs
new format of JEDEC-files
new functions: verify of programmed GALs
test whether security fuse is set or not
compare GALs
optimizer for Boolean equations
reassembler
IMPORTANT CHANGE!!!:
'/' in pin declaration is now considered in the equations
Thanks to: - all registerd GALer users
- Frank Stange for beta-testing
- Walraven van Heeckeren, Wenzel Hoche, Peter Roessel
and Helmut Hohenwarter for parts of the English
documentation
- Colin Fox and Bruce Dawson for the 'req.library'
- Commodore for the great Amiga
Contents:
Chapter I Introduction
I.1 What are GALs
I.2 What is Inside of a GAL?
I.3 What Kind of GALs are there?
I.4 The Operation Modes of a GAL
Chapter II The Software
II.1 The Source File
II.2 The Program "GALer"
II.2.1 Installation
II.2.2 How to use GALer
II.2.3 Menus
II.2.4 Assembler
II.2.5 How to Program GALs
II.2.6 How to Test Programmed GALs
II.2.7 Optimizer
II.3 JEDEC File
II.4 Further Examples
II.5 Error Messages
II.5.1 Assembler
II.5.2 JEDEC File
II.5.3 Reassembler
Chapter III The Hardware
III.1 Programming GALs
III.2 Circuit Description
III.3 Construction
Appendix
Source File Keywords
Parts List
Further Reading
Chapter I: Introduction
=====================
I.1 What are GALs?
------------------
GALs (Generic Array Logic) are programmable logic devices.
By appropriate programming by the user, many standard gate functions
can be resolved into a single GAL chip.
Assuming you need the following logic functions for your circuit:
- AND -Gate with 2 inputs
- OR -Gate with 2 inputs
- NAND-Gate with 2 inputs
- NOR -Gate with 2 inputs
Normally you would need FOUR standard TTL-ICs. These functions can be
replaced with ONE GAL. The main use of GALs is to make digital circuits as
simple as possible, by replacing many standard logic ICs by one or more
GALs. A GAL is able, with appropriate programming, to replace all the logic
functions, such as for example: AND, OR, XOR, NAND, NOR, inverters,
FlipFlops, decoders (especially address decoders), mutiplexers, counters.
On top of all the GAL is reprogrammable (at least 100 times), so that the
desired logic functions may easily be altered.
I.2 What is inside of a GAL?
--------------------------------------
The essential part of a GAL is a matrix. The input pins of the GAL are
connected both inverted and uninverted to the columns of this matrix.
If the GAL hasn't been programmed the rows and columns are connected to
each other. Every connection between a row and a column represents an
AND gate. If the GAL is programmed the particular connections are erased
so that the wanted logic is programmed. A row is called a product term,
because every column (input) that is still connected to a row represents
an AND gate.
Eight of these rows (product terms) are connected via an OR gate with
the so called OLMC (Output Logic Macrocell). So eight product terms can
be ORed together. The OLMC is a "configurable output cell".
What is a "Configurable Output Cell"?
A GAL contains eight of these configurable output cells. These output
cells may be configured as input, combinational output, tristate output,
or register output.
Combinational Output: This output can be HIGH or LOW.
Tristate Output: This output can take one of three states:
HIGH, LOW, and HIGH IMPEDANCE
This is used if you want to tie two outputs together,
but only one may be active.
Register Output: With this output the result of an equation is not
directly coupled to the output, but connected via
a D-FlipFlop. Only on receipt of a clock pulse, is
the signal passed to the output. When /OE is HIGH,
then the output goes HIGH-IMPEDANCE.
Besides the Matrix, a GAL contains extra bits:
( (n) means that these bits are available for each output).
XOR (n) : The result of the digital connection can be negated with this bit.
XOR (n) = 0 : Output is active LOW
XOR (n) = 1 : Output is active HIGH
SYN, AC0, AC1(n):
This bits determine in which mode the GAL works.
There are three main operating modes in which the GAL works:
Mode 1: SYN = 1, AC0 = 0
AC1(n) = 1 : OLMC as input
AC1(n) = 0 : OLMC as combinational output
Mode 2: SYN = 1, AC0 = 1
AC1(n) = 1 : tristate output
Mode 3: SYN = 0, AC0 = 1
AC1(n) = 1 : OLMC as tristate output
AC1(n) = 0 : OLMC as register output
PT0...63: (PT = product term)
These bits indicate whether the rows (product terms) 0...63 in the
GAL's matrix are valid or not.
PTx = 1: AND-junction in the row x is valid.
PTx = 0: AND-junction in the row x is not used (have no effect) on
the output.
(x = between 0 and 63; there are 64 rows in the matrix,
so that each row can be individually activated or deactivated)
All these bits (82 bits) are tied together via the so called Architecture-
Control-Word (ACW). The ACW is described in chapter III.
Signature:
Here are eight bytes for your own use. Normally a short comment or
a version number of the GAL is placed here.
Security fuse: (Security-Bit)
By setting these bit the GAL can be protected from unauthorized copying.
The reading of the logic matrix is no longer possible. Since the rest of
the bits can still be read this protection is not very effective.
Bulk Erase:
By programming this row the whole GAL is erased. Now it is possible to
program the GAL again. A GAL can be reprogrammed about 100 times.
I.3 What kind of GALs are there?
--------------------------------
The most common types of GALs are the standard types GAL16V8, GAL20V8 and the
A and B types GAL16V8A, GAL20V8A. All this GALs are supported by GALer.
A and B type GALs are faster than the standard GALs.
Since there is no greate difference between the standard, A and B type GALs
I will only talk about the standard GALs GAL16V8 and GAL20V8. When there are
any differences between A, B and standard GALs I will mention this extra.
Pin designations:
GAL16V8
---- ----
Input or Clock 1| |20 +5V
Input 2| |19 Configurable Output Cell
Input 3| |18 Configurable Output Cell
Input 4| |17 Configurable Output Cell
Input 6| |15 Configurable Output Cell
Input 7| |14 Configurable Output Cell
Input 8| |13 Configurable Output Cell
Input 9| |12 Configurable Output Cell
GND 10| |11 Input or /OE
---------
GAL20V8
---- ----
Input or Clock 1| |24 +5V
Input 2| |23 Input
Input 3| |22 Configurable Output Cell
Input 4| |21 Configurable Output Cell
Input 5| |20 Configurable Output Cell
Input 6| |19 Configurable Output Cell
Input 7| |18 Configurable Output Cell
Input 8| |17 Configurable Output Cell
Input 9| |16 Configurable Output Cell
Input 10| |15 Configurable Output Cell
Input 11| |14 Input
GND 12| |13 Input or /OE
---------
From the pin designations you can see that the only difference between the
types of GALs is the number of inputs. The choice of GAL then, is dependant
solely on the number of inputs required.
I.4 The Operation Modes of a GAL
--------------------------------
As already explained under I.2, the SYN, AC0 and AC1(n) bits determine
the mode of the GAL. The pin designations of the GAL are determined
by this mode.
GAL16V8:
Mode 1 | Mode 2 | Mode 3 Mode 1 | Mode 2 | Mode 3
--------------------------- --------------------------
| | --- --- | |
In | In | Clock 1| |20 +5V | +5V | +5V
In | In | In 2| |19 In/C | T* | In/T/R
In | In | In 3| |18 In/C | In/T | In/T/R
In | In | In 4| |17 In/C | In/T | In/T/R
In | In | In 5| |16 C | I/T | In/T/R
In | In | In 6| |15 C | In/T | In/T/R
In | In | In 7| |14 In/C | In/T | In/T/R
In | In | In 8| |13 In/C | In/T | In/T/R
In | In | In 9| |12 In/C | T* | In/T/R
GND | GND | GND 10| |11 In | In | /OE
-------
GAL20V8:
Mode 1 | Mode 2 | Mode 3 Mode 1 | Mode 2 | Mode 3
--------------------------- --------------------------
| | --- --- | |
In | In | Clock 1| |24 +5V | +5V | +5V
In | In | In 2| |23 In | In | In
In | In | In 3| |22 In/C | T* | In/T/R
In | In | In 4| |21 In/C | In/T | In/T/R
In | In | In 5| |20 In/C | In/T | In/T/R
In | In | In 6| |19 C | In/T | In/T/R
In | In | In 7| |18 C | In/T | In/T/R
In | In | In 8| |17 In/C | In/T | In/T/R
In | In | In 9| |16 In/C | In/T | In/T/R
In | In | In 10| |15 In/C | T* | In/T/R
In | In | In 11| |14 In | In | In
GND | GND | GND 12| |13 In | In | /OE
-------
Abbreviations:
In : input
C : combinational output without feedback
T : tristate-output
T* : tristate-output without freedback to the matrix, which means
that this output cannot be configured as input
R : register-output
Clock : pulse for D-FlipFlops; only affects those pins which are
configured as register-output
/OE : output enable (low active): activate the register-outputs
(see I.2)
From the pin designations you can see that pins 15 and 16 of the GAL16V8
and pins 18 and 19 of GAL20V8 cannot be programmed as inputs when the GAL is
in mode 1. The same hold true for pins 12 and 19 and 15 and 22 for mode 2.
In mode 1, pins 1 and 11 (GAL16V8) and pins 1 and 13 (GAL20V8) are reserved
for Clock and /OE. These pins therefore cannot be used as inputs.
If you need at least one register output in your GAL, then mode 3 is used.
When you need at least one Tristate-Output and no register output, then the
GAL will be in mode 2. When you need neither a tristate nor a register
output, mode 1 is used.
Chapter II: The Software
========================
In principle you can forget all of chapter I. In principle! What you should
remember is the pin designations of the GAL in the different modes. Thereby
avoiding many unnecessary failures. The determination of the function mode
and the other parameters, which are to be taken into account during the
programming of the GAL, are taken care of by the software.
II.1 The Input File
----------------------
First a source file has to be created with a text editor. This source file
must contain the following information:
1. The GAL type (GAL16V8 or GAL20V8 )
2. an 8 byte long comment, which will be written into the GAL as the
signature (see I.2)
3. The pin names - here pin numbers are replaced with names, which is
easier to oversee.
4. The Boolean equations
5. The keyword DESCRIPTION - after this you can place some desired text.
This text generally describes the GAL's function. That way you can know
years later what the GAL's intended use was.
Before it's getting boreing here is a first example (be happy).
Example 1:
Assuming you need the following gates in your circuit:
- one AND with 3 inputs
- one NAND with 2 Inputs
- one OR with 2 inputs
- one small digital circuit which feeds the outputs from 2 AND gates
to the inputs of one OR gate.
Switch diagram:
(sorry for the European symbols)
AND: +----+ W = A * B * C
A ----| |
B ----| & |---- W
C ----| |
+----+
NAND: +----+ /X = D * E
D ----| |
| & |o--- X
E ----| |
+----+
OR:
+----+ Y = F + G
F ----| |
| >1 |---- Y
G ----| |
+----+
small digital +----+ Z = H * I + J * K
circuit: H ----| |
| & |----+
I ----| | | +----+
+----+ +---| |
| >1 |---- Z
+----+ +---| |
J ----| | | +----+
| & |----+
K ----| |
+----+
Legend:
* : AND - connection
+ : OR - Connection
/ : low active
In order to create the source file we have to determine which type of GAL
will suit our purpose. For the implementation of the above logic functions,
we need a total of 11 inputs and 4 outputs. From chapter I we know
(or not?) that the type of GAL is dependant on the number of needed inputs.
The number of inputs in turn depends on the mode (see I.4, pin designations
of the various modes). Since neither tristate nor register outputs are used,
the GAL will be in mode 1, after programming. It therefore follows, the
GAL16V8 has 10 inputs and 8 configurable outputs. Since we only need 4
outputs, we can program the rest of the outputs as inputs, so that we
obtain the total required 11 inputs and 4 outputs. Therefore GAL16V8 is
adequate for our purposes. GAL20V8 can also be used, but that leaves a lot
of unused inputs (WASTE !).
The second thing we need is a signature for the GAL. Remember, it can
be up to 8 characters long. For example "example".
Now we have to define the pins. The pins are named one after the other
from 1 to 20. Pins that are not used should be named "NC" (not connected),
ground with "GND" and +5V with "VCC".
here: B C D E F G H I J GND
K NC NC NC Z Y X W A VCC
that is:
Pin 1 := B Input
Pin 2 := C Input
Pin 3 := D Input
Pin 4 := E Input
Pin 5 := F Input
Pin 6 := G Input
Pin 7 := H Input
Pin 8 := I Input
Pin 9 := J Input
Pin 10 := GND Ground
Pin 11 := K Input
Pin 12 := NC Not Connected
Pin 13 := NC Not Connected
Pin 14 := NC Not Connected
Pin 15 := Z Combinational Output
Pin 16 := Y Combinational Output
Pin 17 := X Combinational Output
Pin 18 := W Combinational Output
Pin 19 := A (Configurable Output defined as Input)
Pin 20 := VCC Voltage Supply
GAL16V8
---- ----
B 1| |20 VCC
C 2| |19 A
D 3| |18 W
E 4| |17 X
F 5| |16 Y
G 6| |15 Z
H 7| |14 NC
I 8| |13 NC
J 9| |12 NC
GND 10| |11 K
---------
Next come the Boolean equations:
W = A * B * C
/X = D * E
Y = F + G
Z = H * I + J * K
Therewith we have all the parts required for the source file. Now the
question arises, what format does such a file have?:
In line 1 must be the type of GAL. Here "GAL16V8"
In line 2 must be the signature. Here "Example"
Then follow the pin declaration:
B C D E F G H I J GND
K NC NC NC Z Y X W A VCC
Then the Boolean Equations:
W = A * B * C
/X = D * E
Y = F + G
Z = H * I + J * K
and the keyword DESCRIPTION.
Now using a text editor you can create your source file, and save it with
the title "example.pld". Don't forget the extension ".pld".
This is how the file should look:
(**** These characters designate the start and end of the file, please
don't type it.)
******************************************************
GAL16V8 here could be a comment
Example here could be a comment
B C D E F G H I J GND
K NC NC NC Z Y X W A VCC
W = A * B * C
/X = D * E
Y = F + G
Z = H * I + J * K
DESCRIPTION: here could be a comment
******************************************************
Negations ('/') in the pin declaration are considered in the Boolean
equations. This means, if you use a '/' in the pin declaration and
if you use the related pin in a Boolean equation this pin will be
negated.
Example:
--------
A B /C D ..... GND
K L M N ..... VCC
N = C
This is the same:
A B C D ..... GND
K L M N ..... VCC
N = /C
How do you obtain from this source file a programmed GAL? For that you
need the program "GALer".
II.2 The Program "GALer"
------------------------
II.2.1 Installation
-------------------
GALer needs the req.library in your libs: directory. The req.library is
copyright by Colin Fox and Bruce Dawson. You can find this library in the
directory ReqLibrary on your GALer disk. Without this library GALer won't
work.
Configurations are saved to the file "S:GALer.config". If GALer is started and
can't find this file GALer will use defaults.
You can start GALer either from Workbench or CLI.
II.2.2 How to use GALer
-----------------------
All requester can be confirmed or canceled with both mouse or keyboard.
You can use the following keys:
"w": is the same as selecting the "Cont" or "O.K." gadget
"a" oder ESC: is the same as selecting the "Cancel" gadget
"1": select "GAL16V8"
"2": select "GAL16V8A"
"3": select "GAL20V8"
"4": select "GAL20V8A"
GALer uses several files which have different extensions like ".pld", ".jed",
".chp", ".pin", ".fus". If you want to load or save such a file GALer will
choose the right extensions automatically. So you don't have to care about
it. If you don't enter the postfix, GALer will add it.
II.2.3 Menus
------------
Project:
About GALer Tells you who has done all this code. I can tell
you, I was it.
Save config. Saves some settings to the file "S:GALer.config".
Starting GALer next time, GALer will read this file
and set your saved settings again.
Quit Quit quits GALer, but ATTENTION! Handle this function
with care: If you use Quit too often, GALer will sell
your Amiga's CPU.
Are you thinking that I'm pulling your leg?
Ohhhh no..., really not!!! I never would do this.
GAL-Type:
GAL16V8 Here you can select the type of GAL which should be
GAL20V8 read/programmed next time. Since there are no
A-Type principle differences between A and B types there
is no extra menu for the B types, use the A-Type menu
instead.
Auto-A-Type If you don't want to care about whether you have a
A, B type or standard type GAL, select this menu.
GALer will then notice automatically what type of
GAL you have inserted in the socket. You only have
then to choose between 16V8 and 20V8.
Type-Requester Every time when GALer wants to read or program a GAL
GALer will bring up a requester in which you can
select the type of GAL you want to read or program.
This selection overrides the selection in the
GAL16V8, GAL20V8 and A-Type menus.
If you don't want this behavior of GALer, deselect
the Type-Requester menu. GALer will then not bring up
a requester.
GAL:
Program Program a GAL. This is the most importent function of
GALer. After selecting this menu, GALer will bring
up a file requester in which you can select the
JEDEC-file which should be programmed into the GAL.
Copy Copy a GAL. You can only copy a GAL if the security
bit of the source file is not set and if the
destination GAL is not programmed.
Erase Erase a GAL. If you want to program a GAL the GAL
must be erased. Do this with this function.
Compare There are three different types of comparison. You
can compare a GAL with several GALs, a GAL with
several JEDEC files or a JEDEC file with several
GALs.
Blank test Test whether the GAL is erased or not.
Set security bit Set the security bit of a GAL. The logic matrix of
such a protected GAL can't be read out after doing
this.
Test security bit Test whether the security bit of a GAL is set or not.
Write access This function brings up a requester. In this
requester you can select what GALer should do before
or after programming, copying or erasing a GAL.
programming:
- with blank test: before programming a GAL test
whether it is erased or not
- with verify : verify GAL after programming
copying:
- with blank test: test destination GAL whether
it is erased or not
- with verify : verfiy programmed destination
GAL
erasing:
- with blank test: test after erasing a GAL
whether it is really cleared
or not
GAL-Assembler:
Assemble file Assemble a source file (name.pld) and generate
the JEDEC file and some special files.
GAL-Disassembler:
Read signature Read signature of a programmed GAL and print it
on the screen.
Read ACW Read the architecture control word of a GAL and
print it on the screen.
GAL-Info Gives you some information about your GAL.
generate JEDEC-file Read a GAL and make a corresponding JEDEC file.
JEDEC-file parameter Selecting this menu puts up a requester in which
you can determine parameters concerning the writing
of JEDEC files.
Security bit: If this is enabled, GALer will write
JEDEC files in which a special flag is set.
Reading this JEDEC file to program a GAL will bring
up a requester in which you can choose to set the
security bit after programming or not.
Fuse-Checksum: If this is enabled, GALer will write
JEDEC files with a checksum calculated over all
fuses. Manually changed fuses (with text editor)
will be detected by GALer and GALer will warn you
that this JEDEC file has been changed when reading
this file next time. You are allowed to change
comments etc. but you are not allowed to change
fuses ('0' and '1').
File-Checksum: If this is enabled, GALer will write
JEDEC files with a checksum calculated over all
characters in this file. This means that you are
not allowed to change anything in this file
by using a text editor.
Reassembler This function reads a JEDEC file and generates then
the original source file. So you can read a unkown
GAL and get back a source file with the Boolean
equations.
Tools:
Show pinnames Prints the pin names of the last assembled source
file on the screen.
Clear pinnames Clears pin names from screen.
GAL-Checker There you can check a programmed GAL whether it does
this what you want to do it or not. See corresponding
paragraph.
Optimizer Optimize Boolean equations. See corresponding
paragraph.
II.2.4 Assembler
----------------
In order to program a GAL the source file (".pld") must be transposed into a
so called JEDEC file. This task is assumed by the GAL-Assembler. The
JEDEC file (extension ".jed") is a ASCII file in which all the bits which
can be set in a GAL are listed. The state of the fuses (0 or 1) is
mediated by the GAL-Assembler from the source file. Besides the JEDEC file,
the GAL-Assembler can generate three other files. This files are for
documentation only. GALer do not need them:
The Fuse-File (extension ".fus") shows the state of the bits in the
logic matrix. The Chip-Diagram (extension ".chp") shows the connection
diagram of the GAL and the Pin-Diagram file (extension ".pin") lists
all the pins and shows, whether these are programmed as inputs or outputs.
The files can be read with a text-editor and possibly post-processed.
Selecting the menu 'Assemble file' pops up a requester, called
assembler requester. In the assembler requester you can select which
files should be generated by the assembler. Just click on the corresponding
gadget.
Furthermore you can select two other gadgets:
Autosave: This means that all selected files are generated
automatically without bringing up an extra file requester.
The name of the generated files are taken from the
source file name.
Adjust type of GAL: This means that the type of GAL for which the
source file is, is taken over from GALer.
For example: You have set a GAL20V8 in GALer's menu.
Now you are assembling a source file for a GAL16V8. If the
assembly is successful, GAL16V8 will be set in GALer's menu.
Selecting the 'Count' (countinue) gadget of the assembler requester
will pop up a file requester. Now you have to choose your source
file. After this the GAL assembler will start assembling. If GALer
detects no errors, a second file requester will pop up. Now you have
to save your JEDEC file.
II.2.5 How to Program GALs
---------------------------
After the GAL-Assembler has created the JEDEC file from the source file,
the GAL can be programmed using this JEDEC file. To initiate the
programming of the GAL, simply select 'Program' and give the JEDEC file
name. As soon as the GAL is programmed, a requester pops up, and tells
you the GAL is programmed, and it is OK to remove the GAL from the
programmer's socket.
The steps in programming a GAL:
1. With a Text editor create the source file and save this
file as "name.pld" (add the extension .pld!)
2. Assemble the source file -> JEDEC file ("name.jed")
3. Select the GAL type (GAL16V8, GAL20V8)
4. Insert the GAL in the Programmer's socket
5. Perform the 'Blank test' to verify that the GAL is empty.
When the GAL is not empty, then you must first erase the GAL
before it can be programmed, use therefore the function 'Erase'.
6. Initiate programming by selecting 'Program'.
7. Take the GAL out of the programmer's socket, - DONE !
II.2.6 How to Test Programmed GALs
----------------------------------
Once the GAL has been programmed, the question remains, "does it work the
way you envisaged it?". This is the purpose of the GAL-Checker. In order to
verify the GAL's functions, you must of course first plug the GAL into the
programmer's socket, and select the correct GAL-type. Now you can select
the menu item GAL-Checker. In the middle of the screen you'll see a
symbolic GAL displayed. In this GAL, you'll see a number of 'I's and 'O's.
The 'I' stands for Input and the 'O' for Output. The 'O' is a gadget. By
clicking on the 'O' it turns into an 'I' and clicking on it again it
becomes an 'O' again. In other words, you can determine if this pin is
to be used as an input or an output. If a pin is an input, then you can
select from another gadget if the pin is to be in a "High" ('H') or in a
"Low" ('L') state. The outputs have a green border. An output can assume
three states: 'H' (High), 'L' (Low) and 'Z' (high impedance). If you're
using the GAL from the above example, pin 19 must be defined as an
input (="A") by clicking on the 'O' (the one by pin 19), since this pin
was defined as an input during programming in the above example. The
inputs of the AND gate are: pin 19 (="A"), pin 1 (="B"), pin 2 (="C").
The output is pin 18 (="W"). If you now set the inputs of the AND gate
HIGH (by clicking on the gadgets), the output (=pin 18) should also go
HIGH. If it doesn't work or if the output also goes high with other
combinations of input levels, then the fault is probably in the source
file. The error should be corrected in the source file. The GAL must
then be erased and reprogrammed (a GAL can be erased and reprogrammed at
least a hundred times). In this manner the whole GAL can be fully
tested, and if no errors are detected, can be used in your circuit.
II.2.7 Optimizer
----------------
Boolean equations can be simplified very often, but for human beings
it is a hard way to do. A computer can do this much faster (in most
times). The Optimizer of GALer tries to optimize Boolean equations
by use of the Quine-McCluskey algorithm. How this algorithm works
you can read in many books which deal with Boolean mathamatics.
The usage of the Optimizer:
Just select the menu 'Tools - Optimizer' to start GALer's Optimizer.
After this a file requester pops up. Now you have to select the source
file which equations you want to be optimized.
After successfully loading this source file GALer starts to optimize
the equations.
GALer displays the original equation and the optimized one. If you
are happy with the result of the optimization you should select the
gadget 'use it'. Then the original equation is replaced by the
optimized equation in your loaded source file. If you don't like the
result of the optimization, you should select the gadget 'reject'. Then
the original equation is not replaced. After trying to optimize all
equations GALer will pop up a file requester again. Now you have to
select a file name of your optimized source file. Please don't use the
file name of the original source file for the optimized source file.
Example of optimization:
Original Boolean equation:
X = /A*/C + A*/C + C*/D + /B*/C + /A*C*D + B*/D
By GALer optimized Boolean equation:
X = /C + /D + /A
Both equations are equal, but the second one is much easier to read.
Not all equations can be simplified. It could be that a "optimized"
equation is more complicate than the original one. Just try it.
II.3 JEDEC File
---------------
JEDEC means (J)oint (E)lectron (D)evice (E)nineering (C)ouncil.
This file is a ASCII file in which every bit which can be set in a
GAL is listed. The JEDEC file has the extension ".jed" and it's
generated by the GAL-Assembler.
The JEDEC file can start with any text until there is a asterisk (*).
The first '*' introduces the command field. The command field starts
with the first '*' and ends at the file end. Within the command field
are... (now be astonished) commands! A command is introduced by one
character and it ends with a '*' character.
All commands are optional. Not every command must be in a JEDEC file.
The GAL-Assembler normaly uses: L, F and G commands (see below)
Possible commands are:
N: This introduces a comment.
Example: N this is a comment *
^ ^ ^
| | |
command any text end of command
F: You don't have to list all states of the fuses in the GAL. If you don't
list all fuses GALer must know what the state of the missed fuses is.
F0 *: not listed fuses are set to 0
F1 *: not listed fuses are set to 1
G: Security Fuse
G0 *: don't set the security fuse after programming the GAL
G1 *: ask user (you) whether to set the security fuse after
programming the GAL or not
L: L defines the address of a fuse and what the state of the fuse
should be.
Example: L0000 10110111111111111111111111011111 *
this means: set fuse at address 0 to 1
set fuse at address 1 to 0
set fuse at address 2 to 1
.
.
.
possible addresses are:
GAL16V8, GA16V8A, GAL16V8B:
0000-2047: matrix of fuses
2048-2055: XOR bits
2056-2119: signature
2120-2127: AC1 bits
2128-2191: product term disable bits
2192 : SYN bit
2193 : AC0 bit
GAL20V8, GAL20V8A, GAL20V8B:
0000-2559: matrix of fuses
2560-2567: XOR bits
2568-2631: signature
2632-2639: AC1 bits
2640-2703: product term disable bits
2704 : SYN bit
2705 : AC0 bit
QF: Defines how many fuses in the JEDEC file are. A GAL16V8 has
2194 fuses and a GAL20V8 has 2706 fuses. Now GALer can
identify for which type of GAL this JEDEC file is.
Example: QF2194 *
C: C is followed by a 16 bit hex number which is the fuse checksum of
the JEDEC file (see description of menu 'JEDEC-file parameter').
Example: C6402 *
<STX>, <ETX>: This are control characters.
<STX>: 0x02 = CTRL-B
<ETX>: 0x03 = CTRL-C
Your text editor displays this characters in this way:
<STX>
<ETX>
<STX> defines the start of the JEDEC file and <ETX> the end of the
JEDEC file. <ETX> is followed by the file checksum (see description
of menu 'JEDEC file-parameter'). The file checksum is a 16 bit hex
number.
V: V introduces a test vector. GALer 1.4 does not support this. GALer
interprets this command as a N command (comment).
II.3 Further Examples
----------------------
Next I want to show an example with a tristate output.
(sorry again for the European symbols)
/A ---------+
|\|
| \
B -------| +------------------------ Y1
| /
|/
VCC
|
+----+ |\|
C -------| | | \
| >1 |-----------| +------- Y2
D -------| | | /
+----+ |/
+----+
E -------| |
| & |------+
F -------| | |
+----+ |
|\|
| \
G -----------------| +o------------- Y3
| /
|/
Y1 should only be in the "B" state, when "A" = LOW. Y2 should always be
active (either HIGH or LOW - depending on "B" and "C"). This corresponds
to a combinational output. Y3 should only be active if "D" and "E" = HIGH.
GAL16V8
---- ----
A 1| |20 VCC
B 2| |19 Y1
C 3| |18 Y2
D 4| |17 Y3
E 5| |16 NC
F 6| |15 NC
G 7| |14 NC
NC 8| |13 NC
NC 9| |12 NC
GND 10| |11 NC
---------
In the source file, tristate outputs are designated with a ".T". The
tristate control is followed with an ".E". If the tristate control
is absent then the normal free switching is assumed (=VCC). Tristate
control = GND means high impedance. NOTE: With tristate outputs you can
only have seven product terms in your equation (all other output formats
have a maximum of eight). In the tristate control you can only have ONE
product term (no OR) in your equation.
The Source file looks like this:
******************************************************
GAL16V8
ex.2
A B C D E F G NC NC GND
NC NC NC NC NC NC Y3 Y2 Y1 VCC
Y1.T = B
Y2.T = C + D
Y3.T = /G
Y1.E = /A
Y3.E = E * F
DESCRIPTION
******************************************************
For the last example we will deal with register outputs.
First the pin declaration:
GAL16V8
---- ----
(Input) Clock 1| |20 VCC
(Input) D0 2| |19 Q0 (Output)
(Input) D1 3| |18 Q1 (Output)
(Input) D2 4| |17 Q2 (Output)
(Input) D3 5| |16 Q3 (Output)
(Input) Set 6| |15 NC (not used)
(Input) Clear 7| |14 NC (not used)
(Input) NC 8| |13 NC (not used)
(Input) NC 9| |12 NC (not used)
GND 10| |11 /OE (Input)
---------
Since register output sets the GAL in mode 3, this means that pins 1
and 11 are reserved for Clock and /OE. When /OE is HIGH, all register
outputs (Q0-Q3) go to "high impedance" (=Z). When LOW-HIGH transition
pulse is presented at the clock input, then the counter will be
incremented. When Clear = HIGH and a (LOW-HIGH) clock transition occurs,
the outputs are cleared. The inputs D0-D3 can be used to preset the
counter. While Set = HIGH and a Clock pulse the values in D0-D3 are
transferred to Q0-Q3.
In the source file register outputs are designated with an ".R".
******************************************************
GAL16V8 4-Bit-Counter
Counter
Clock D0 D1 D2 D3 Set Clear NC NC GND
/OE NC NC NC NC Q3 Q2 Q1 Q0 VCC
Q0.R = /Clear * Set * D0
+ /Clear * /Set * /Q0
Q1.R = /Clear * Set * D1
+ /Clear * /Set * /Q1 * Q0
+ /Clear * /Set * Q1 * /Q0
Q2.R = /Clear * Set * D2
+ /Clear * /Set * Q2 * /Q1
+ /Clear * /Set * Q2 * /Q0
+ /Clear * /Set * /Q2 * Q1 * Q0
Q3.R = /Clear * Set * D3
+ /Clear * /Set * Q3 * /Q2
+ /Clear * /Set * Q3 * /Q1
+ /Clear * /Set * Q3 * /Q0
+ /Clear * /Set * /Q3 * Q2 * Q1 * Q0
DESCRIPTION
******************************************************
II.5 Error Messages
-------------------
Now I want to describe all possible error messages which GALer can
create.
II.5.1 Assembler
----------------
"Line 1: type of GAL expected"
The first line of your source file must define for what type of GAL
this source file is. So the first line must contain one of the
following keywords: GAL16V8, GAL20V8, GAL16V8A, GAL20V8A
"unexpected end of file"
Normaly this error occurs when there is no DESCRIPTION keyword
at the end of your Boolean equations.
"pin name expected after '/'"
A '/' must be followed by a pin name. If there is a '/' but no pin name
this error will occur.
"max. length of pin name is 8 characters"
Pin names are not allowed to be longer than 8 characters.
"illegal character in pin declaration"
In a pin name is a character which is not allowed to use. Possible
characters are: a..z, A..Z, 0..9, /
"illegal VCC/GND assignment"
VCC and GND are keywords. It's not allowed to use this words for
other pins. Use it only for the pins VCC and GND.
"pn declaration: expected VCC at VCC pin"
The pin VCC must have the name VCC.
"pin declaration: expected GND at GND pin"
The pin GND must have the name GND.
"pin name defined twice"
In the pin declaration a pin name is used multiple.
"illegal use of '/'"
Negations ('/') must be followed by a pin name.
"unknown pin name"
Within a Boolean equation is a undefined pin name.
"NC (Not Connected) is not allowed in logic equations"
NC is a keyword for unused pins. So don't use this in your
Boolean equations.
"'T', 'E' or 'R' expected after '.'"
A '.' must be followed by a T, E or R. This defines an output pin
as tristate or register. E defines a equation for the tristate
enable.
"'=' expected"
A '=' is expected but not found (what else should I say).
"this pin can't be used as output"
You have tried to define a pin as output which can't be used as output.
"same pin is defined multible as output"
It's easier to show an example:
X = ...
X = ...
This brings up this error message.
"Tristate control: tristate output is not defined"
You have defined a Boolean equation for tristate enable but there
was no Boolean equation for the trisate output.
The order must be:
name.T = ...
name.E = ...
Possibly you have done:
name.E = ...
name.T = ...
this is wrong!
"Mode 2: pins 12, 19 can't be used as input"
The GAL would be in mode 2. In this mode you can't define the pins
12 and 19 as input pins. This pins do not have a feedback too. This
means that the following equation is not allowed.
a := pin 19
b := pin 4
y := pin 17
a = b a is output, b is input
y = a * b y is output
a is used as input, this is not allowed in mode 2
because there is on feedback
"Mode 2: pins 15, 22 can't be used as input"
The GAL would be in mode 2. In this mode you can't define the pins
15 and 22 as input pins. This pins do not have a feedback too. This
means that the following eqauation is not allowed.
a := pin 22
b := pin 4
y := pin 17
a = b a is output, b is input
y = a * b y is output
a is used as input, this is not allowed in mode 2
"Tristate control is defined twice"
Example: name.E = A * B
name.E = C
this is not allowed!
"Tristate control for registered output"
name.E is only allowed for tristate outputs. You have used it for a
register output.
"Tristate control without previous '.T'"
There is a tristate control for a combinational output.
wrong: name = ...
name.E = ...
right: name.T = ...
name.E = ...
"use GND, VCC instead of /VCC, /GND"
I think there is nothing to explain.
"Mode 3: pins 1,11 are reservated for 'Clock' and '/OE'"
Using register outputs causes mode 3 for the GAL. In this mode the
pins 1 and 11 of a GAL16V8 can't be used by your own. This pins are
reserved for Clock and /OE.
"Mode 3: pins 1,13 are reservated for 'Clock' and '/OE'"
Using register outputs causes mode 3 for the GAL. In this mode the
pins 1 and 13 of a GAL20V8 can't be used by your own. This pins are
reserved for Clock and /OE.
"use of VCC and GND is not allowed in equations"
Expressions like "X = A * VCC" are not allowed (and not necassary).
"Tristate control: only one product term allowed (no '+')"
In Boolean equations for tristate controls only one product
term can be used. This means no ORs in your name.E=... equation.
"max. 8 product terms allowed"
In Boolean equations for combinational and register outputs a maximum
of eight product terms is allowed. This means that you can use a
maximum of seven ORs in your equations.
"max. 7 product terms allowed"
In Boolean equations for tristate outputs a maximum of seven product
terms is allowed. This means that you can use a maximum of six ORs in
your equations. The eighth product term is used for the tristate control.
"no equations found"
Sorry, but there are no Boolean equations in your source file. So GALer
does not know what to do with your source file.
II.5.2 JEDEC File
-----------------
"unexpected end of file"
The last thing in a JEDEC file should be either the file checksum or
a '*'.
"unknown command found"
There is a unknown command in your JEDEC file (see chapter JEDEC File for
possible commands). In most cases the reason for this error message
is a missing '*'.
"bad format of number"
A dez. or hex. number is expected and found, but there are illegal
characters in it.
Example: C1a#3
"number expected after command"
After this command a dez. or hex. number is expected but not found.
"0 or 1 expected"
Fuses can be set to 0 or 1. Using another digit will cause this error.
"can't find out type of GAL"
GALer can't identify for which type of GAL (GAL16V8 or GAL20V8) this
JEDEC file is. But GALer must know this in order to program a GAL.
"QF multible found"
In the JEDEC file the command QF is found multiple. This is not
allowed.
"QP multible found"
In the JEDEC file the command QP is found multiple. This is not
allowed.
"ending '*' expected"
GALer expects a '*' character.
"after 'C' command no 'L' command allowed"
After the fuse checksum no change of fuses (L command) is allowed.
"bad fuse checksum"
The fuse checksum is bad. The reason for this can be that you have
changed some state of fuses with a text editor.
"too many <STX> (= CTRL-B, 0x02) found"
The <STX> control character should be once at the beginning of the
JEDEC file.
"too many <ETX> (= CTRL-C, 0x03) found"
The <ETX> control character should be once at the end of the
JEDEC file.
"bad sequence of <STX>, <ETX>"
The first control character must be a <STX> then a <ETX> not vice versa.
"after file checksum end of file expected"
There is a character after a file checksum which is not a Space, TAB
or Carriage Return. This is not allowed.
"bad fuse address (L... too short)"
It's easier to show an example:
L0010 1011*
L0013 0111*
Address 13 is defined twice.
"addresses skiped but no default value (F0/1*) defined"
It's easier to show an example:
L0010 11*
L0015 01*
The fuses of the addresses 12, 13 and 14 are not defined and there
is no F command which would define the values of missing fuses.
"'*' expected"
'*' expected but not found (what else should I say here).
"QF... and last fuse address (L...) are not equal"
QF defines the number of fuses in this JEDEC file (GAL16V8: 2194,
GAL20V8: 2706). If the last fuse of a L command does not match
to the QF command, this error will occur.
"no values for the fuses found (no F0/1, L...)"
In your JEDEC file are no fuses defined. Such a file is useless
and therefore rejected by GALer.
"only QF2194* (GAL16V8) and QF2706* (GAL20V8) allowed"
There is a QF command followed with a number not equal 2194 or 2706.
"too many fuses found (>2706)"
In your JEDEC file are too many fuses defined.
"found several fuse checksumms"
In your JEDEC file are several fuse checksumms. This is not allowed.
"selected type of GAL fits not to JEDEC file"
You have selected a to-be-programmed-GAL which does not fit to
the JEDEC file.
II.5.3 Reassembler
------------------
"Mode AC0 = SYN = 0 is not supported"
In the JEDEC file the bits AC0 and SYN are set to 0. This mode
is not supported by GALer.
"Pin xx: pin name defined twice"
A pin name is used for more than one pin.
"Pin xx: illegal character"
Legal characters are : digits, letters and the '/'
Illegal characters are: Space, #, *, ...
"Pin xx: no pin name found"
There is no name for the pin xx defined.
"Pin xx: VCC/GND at wrong pin"
VCC and GND must be the pin names for the VCC and GND pin of the GAL.
"Pin xx: illegal use of '/'"
Usage of the negation character: /pinname
Illegal: pinname/, /, //pinname etc.
"Pin xx: GND expected"
Pin 10 of GAL16V8 respectively pin 12 of GAL20V8 must be defined as GND.
"Pin xx: VCC expected"
Pin 20 of GAL16V8 respectively pin 24 of GAL20V8 must be defined as VCC.
Chapter III: The Hardware
=========================
III.1 Programming GALs
----------------------
The first question that arises is how can you program a GAL when all the
pins are already defined and no pins are free for the programming. If
you apply a voltage of 16.5 V to pin 2 of a GAL, then the pin description
change, the GAL is then in the Edit mode.
GAL16V8
---- ----
VIL 1| |20 +5V
EDIT 2| |19 P,/V
RAG1 3| |18 RAG0
RAG2 4| |17 VIL
RAG3 5| |16 VIL
RAG4 6| |15 VIL
RAG5 7| |14 VIL
SCLK 8| |13 VIL
SDIN 9| |12 SDOUT
GND 10| |11 /STR
---------
GAL20V8
---- ----
VIL 1| |24 +5V
EDIT 2| |23 VIL
RAG1 3| |22 P,/V
RAG2 4| |21 RAG0
RAG3 5| |20 VIL
VIL 6| |19 VIL
VIL 7| |18 VIL
RAG4 8| |17 VIL
RAG5 9| |16 VIL
SCLK 10| |15 SDOUT
SDIN 11| |14 VIL
GND 12| |13 /STR
---------
Whether the GAL is to be read from or written to is determined by the level
of P,/V. A HIGH means write, a LOW read. The to be read/written addresses
are presented to pins RAG0-RAG5. The programming occurs as follows: After
giving the addresses to RAG0-RAG5, the to be written bits have to be
presented to SDIN (serially) and by clocking SCLK with a LOW-HIGH-transition
the data is transferred to an internal shift register. A LOW-pulse on the
/STR pin programs the addressed row. This repeats until the whole GAL is
programmed.
The reading of a GAL proceeds similarly: After presenting the addresses to
RAG0-RAG5 the bits of the corresponding address are put into the internal
shift register by clocking /STR with a LOW-pulse. By clocking SCLK with a
LOW-HIGH-clock transition all the various bits are sent out the SDOUT pin.
The bit width of an address determines the number of SCLK pulses required
to complete the programming or reading the address.
VIL means Input Voltage Low. This pins must be connected to ground
or LOW when the GAL is in the Edit mode.
GALs do have different algorithm codes. This codes determine the parameters
Edit mode voltage and STR pulse width. GALer supports the algorithm codes
0 to 4. The function 'GAL-Info' of GALer returns the algorithm code of
the inserted GAL. This code is not very importent for you, but GALer needs
this code for reading and programming GALs.
| READ | PROGRAM
------------+----------------------------+----------------------------
Algorithm | Edit mode | STR pulse | Edit mode | STR pulse
| read voltage | | prog. voltage |
------------+---------------+------------+----------------+-----------
0 | 12 ± 0,25 V | 5 us | 15,75 ± 0,25 V | 80 ± 5 ms
1 | 12 ± 0,25 V | 5 us | 15,75 ± 0,25 V | 80 ± 5 ms
2 | 12 ± 0,25 V | 5 us | 16,50 ± 0,25 V | 10 ± 1 ms
3 | 12 ± 0,25 V | 5 us | 14,50 ± 0,25 V | 40 ± 5 ms
4 | 12 ± 0,25 V | 5 us | 14,00 ± 0,25 V |100 ± 5 ms
To erase a GAL you have to apply HIGH to P/V then pulse STR low for
100 ms and then apply LOW to P/V. After this the GAL is erased and ready
to be programmed again.
The internal organization of the GAL (addresses of the parts) looks as
follows:
GAL16V8, GAL16V8A,B:
Address Width
0-31 Fuse-Matrix 64 Bit
32 Signature 64 Bit
33-59 reserved space 64 Bit
60 Architecture-Control-Word ACW 82 Bit
61 Security bit
62 reserved
63 Bulk Erase
GAL20V8, GAL20V8A,B:
Address Width
0-39 Fuse-Matrix 64 Bit
40 Signature 64 Bit
41-59 reserved space 64 Bit
60 Architecture-Control-Word ACW 82 Bit
61 Security bit
62 reserved
63 Bulk Erase
The Architecture-Control-Word has the following structure (82 Bit wide):
GAL16V8:
Bits 0-31: 32 bit product term enable 0-31
Bits 32-35: 4 Bit XOR(n) for OLMC pins 19-16
Bit 36: AC0-Bit
Bits 37-44: 8 Bit AC1(n) for OLMC pins 19-12
Bit 45: SYN-Bit
Bits 46-49: 4 Bit XOR(n) for OLMC pins 15-12
Bits 50-81: 32 Bit product term enable 32-63
GAL16V8A,B:
Bits 0-3: 4 Bit XOR(n) for OLMC pins 19-16
Bit 4: AC0
Bit 5-8: 4 Bit AC1(n) for OLMC pins 19-16
Bit 9-72: 64 Bit product term enable PT0 - PT63
Bit 73-76: 4 Bit AC1(n) for OLMC pins 15-12
Bit 77: SYN
Bit 78-81: 4 Bit XOR(n) for OLMC pins 15-12
GAL20V8:
Bits 0-31: 32 Bit product term enable 0-31
Bits 32-35: 4 Bit XOR(n) for OLMC pins 22-19
Bit 36: AC0-Bit
Bits 37-44: 8 Bit AC1(n) für OLMC pins 22-15
Bit 45: SYN-Bit
Bits 46-49: 4 Bit XOR(n) für OLMC pins 18-15
Bits 50-81: 32 Bit product term enable 32-63
GAL20V8A,B:
Bits 0-3: 4 Bit XOR(n) for OLMC pins 22-19
Bit 4: AC0
Bit 5-8: 4 Bit AC1(n) for OLMC pins 22-19
Bit 9-72: 64 Bit product term enable PT0 - PT63
Bit 73-76: 4 Bit AC1(n) for OLMC pins 18-15
Bit 77: SYN
Bit 78-81: 4 Bit XOR(n) for OLMC pins 18-15
III.2 Circuit Description
------------------------------
In the following section I'll describe the functioning of my GAL-Programming
Device. I'll refer to my circuit diagram, so if you haven't ordered that,
you can skip this section.
The hardware is connected to the Amiga's parallel port. The connected data
signals are D0-D4 and the BUSY-Line.
IC1, IC3, IC4 and IC5 are eight way "serial in/parallel out" shift registers.
The outputs of the shift-register from IC3, IC4 and IC5 are connected to the
Textool-Zero insertion force socket for the GAL. Therefore it is possible to
(besides VCC and GND) define each of the GAL's pins with a level (HIGH or
LOW). The possible outputs of the GAL (pin 14 to 22) can be read through
IC7 and IC6a . IC7 is an eight way "parallel in/serial out" shift register.
IC1 is so to speak the switch centre, this IC selects IC3, 4 and 5 (OE).
Furthermore, this IC switches the programming voltages for the GAL (VCC,
Edit-voltage) on or off. Since the ICs 1, 3, 4, 5, 7 can be individually
accessed, a separate clock line is provided for each IC. These clock lines
are selected via IC2, a 1 out of 4-Decoder, by the parallel port's data lines
D0 and D1. D3 determines whether a read (low) or write (high) operation is
to occur. You must ensure that D3 does not go low until the IC to be
accessed is selected through D0 and D1. Otherwise an IC gets an unwanted
clock-pulse and at the next Strobe-pulse (D2) the wrong (once left shifted)
data is presented at the outputs. The Strobe-pulse for the shift-register is
derived from D2 . When D2 goes high, the data in the shift registers is
transferred to the output registers of ICs 1, 3, 4, 5 . Through IC7, D2 can
be made high (D2 = high), so that the data on Pins P1-P8 are transferred to
the internal shift register and may be read through the BUSY line by clocking
the relevant clock-line. D4 transfers the individual bits from the Amiga to
the GAL-Burner. Since Pins 2 and 4 of the Textool-socket may be supplied with
the programming voltage of up to 16.5 Volt, we have to protect IC4 with the
diodes D2 and D3 against over voltage. The programming voltage is derived
from IC9, a switch mode voltage regulator. This voltage can be precisely
adjusted with the trimpots R40-R44.
The relay K1 connects the supply voltage of the GAL to
pin 24 of the Textool-Socket, Relay K2 connects the output Q7 from IC3 or +5V
supply voltage (according to the GAL type) to Pin 22 of the Textool-Socket.
Both relays are driven by IC1. The LED shows whether voltage is supplied to
the Textool-Socket or not. When the LED is on, a GAL may not be inserted or
removed from the socket.
Parallel-Port:
D0-D1: Selection of individual ICs by Clk
D2: Strobe-pulse for IC 1, 3, 4, 5
D3: write = low, read = high
D4: Data line for "Write Bits"
BUSY: Data line for "Read Bits"
IC1:
Q1 make 16.5V (but don't switch it!)
Q2 switch edit-current on pin 2 for GAL20V8
Q3 switch edit-current on pin 4 for GAL16V8
Q5 switch Vcc
Q6 OE for IC3, 4, 5
Q7 controlles LED on : high, low = off
Q8 not used
IC3:
Q1-Q8 pin 16-23 of the Textool-socket over R3-R8
IC4:
Q1-Q8 pin 1-8 of the Textool-socket
IC5:
Q1-Q3 pin 9-11 of the Textool-socket
Q4 pin 13 of the Textool-socket
Q5-Q6 pins 14, 15 of the Textool-socket over R9, R10
IC6:
a read pin 13 of the Textool-socket
b read buffer of IC7
IC7:
P1-P8 read pin 14-21 of the Textool-socket
III.3 Construction
----------------------
The parts list can be found in the appendix. If you want to save the cost
of the Textool-socket, you can also use a normal 24 pin socket, but since the
two pin rows are too far apart, you will have to carefully cut the socket
along it's length, and set them to the correct distance. Or you might like
to use "MOLEX" pins instead. For IC-sockets you should only use precision
sockets. The 25 Pin Sub-D-socket (A1000) or the Sub-D-plug (other Amiga
models) is connected as follows:
D0 = pin 2
D1 = pin 3
D2 = pin 4
D3 = pin 5
D4 = pin 6
BUSY = pin 11
GND : A1000 pin 14
A500, A2000, A3000, ... pin 17
The supply voltage (+5V and ground (GND) you will have to get from the
Amiga's Expansion-Port or from a regulated +5V power supply. The GAL-Burner
has a maximum current consumption of about 220 mA.
The main difficulty in the construction of the GAL-burner is probably the
PC board. Most likely a double sided through plated PCB is required, so
probably the best solution is to use a piece of veroboard, and connect the
relevant pins with fine hookup wire, or wire wrap wire. If you want the whole
thing to look impressive, you can use wiring guides. The wires can be
conducted via these guides, and wont go here there an everywhere. I have
constructed my GAL-Burner and endless other projects in this way.
When you have built the circuit and you have connected it to the Amiga,
and the Amiga DIDN'T blow up, you can run the test program "GALerTest".
The program set various voltage levels on the Textool-socket, which you
can check with a VOM. The programming voltages are adjusted with R40-R44.
For this you can use "GALerTest".
DON'T FORGET: adjust the programming voltage with the trimpots, otherwise
the GAL-burner will NOT FUNCTION !!!!
(start the "GALerTest" and click through to the relevant test points). If
the GAL-Burner works just as the test program demands, then you can try
burning a test GAL and test it with the GAL-Checker function of GALer. IF
this all works then there are no faults in the hardware. GALs of the type
GAL16V8 must be inserted in the Textool-socket, so that pin 1 of the GAL
lines up with pin 3 of the socket. With GALs of the type GAL20V8 pin 1 of
the GAL must line up with pin 1 of the socket.
Well that's about it. Chau and have fun with the cute GALs.
**************************************************************************
Appendix
======
Keywords of the Source File:
----------------------------
GAL16V8, GAL20V8 designates the GAL-Type
GAL16V8A, GAL20V8A
NC not connected (unused) pin
GND GROUND (=LOW)
VCC +5V (=HIGH)
.T output pin is tristate output
.E tristate enable through product term
.R output pin is register output
= output pin is given an equivalence
+ OR
* AND
/ NOT
DESCRIPTION indicates the end of the Boolean equations
Parts list:
------------
ICs:
----
IC1, IC3, IC4, IC5 : 4 x 4094
IC2 : 1 x 4555
IC6 : 1 x 4503
IC7 : 1 x 4021
IC8 : 1 x 74LS06
IC9 : 1 x TL 497
IC10 : 1 x 74LS145
Diodes:
-------
D1-D4 : 4 x 1N4148
LED : 1 x rot, 3 mm
Transistors:
------------
T2, T4, T5 : 3 x BC237B
T1, T3 : 2 x BC327
Resistors (5%, 1/4 Watt):
-------------------------
R1, R2, R35-39 : 7 x 1 KOhm
R3-13, R19-26 : 19 x 10 KOhm
R28-32 : 5 x 1,8 KOhm
R14 : 1 x 1 Ohm
R15 : 1 x 47 KOhm
R34 : 1 x 220 Ohm
R18 : 1 x 4,7 Ohm
R27 : 1 x 47 Ohm
R33 : 1 x 22 KOhm
R40-44 : 5 x 1 KOhm trimpots
(there are no R16, R17)
Relays:
-------
K1, K2 : 2 x relays with 5V or 6V, 1 x single
pole double throw
Coil:
-----
L1 : 1 x 100 uH, miniature fixed
Kondensatoren:
--------------
C1 : 1 x 100 pF
C2 : 1 x 4,7 uF, tantalum
C3 : 1 x 100 nF
C4 : 1 x 220 uF, 25V
Sundries:
----------
IC-Sockets
8 x 16 pin
2 x 14 pin
1 x Textool-Socket 24 pin, narrow! (.3 row spacing) or use
a universal type
1 x 25 pin female Sub-D connector for Amiga 1000
or 25 pin male Sub-D connector for all other Amiga types
u = mikro
Bibliography:
------------------
1) GALs - Programmierbare Logikbausteine in Theorie and Praxis
Bitterle
Franzis-Verlag
This book (German) is well suited for beginners.
2) Programmable Logic Manual - GAL Products
SGS-Thomson
This book (english) is for the pro.
