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timing.doc
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1986-02-21
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SECTION PAGE #
INTRODUCTION
Purpose of this software .................. 1
Current Capability ...................... 1
Future Enhancements ..................... 2
Support for Abel ...................... 2
Support for Cupl ...................... 2
Reduction of Boolean Equations ........ 2
GETTING STARTED
Hardware Requirement ...................... 3
Minimum Required System ................. 3
Recomended Hardware ..................... 3
Main Menu Commands ........................ 4
Naming the pins ......................... 4
Entering the signal list order .......... 4
Drawing the signals on the screen ....... 4
Creating the PALasm 2 formated file ..... 5
How to exit and save your work .......... 6
How to exit without saving your work .... 6
SAMPLE DESIGNS
4 bit counter .............................
with reset ..............................
with set, reset, and load ...............
8 bit ring counter ........................
with reset ..............................
with reset and hold .....................
ADVANCED FEATURES
More than one state machine in a PAL ......
Extended simulation capability ............
Designing a continuous counter ............
LIMITATIONS
*** CAUTION *** ...........................
WHO TO CONTACT WITH PROBLEMS ................
A. INTRODUCTION
1. Purpose of this software
a) Current Capability
The TiDE program is very nearly a finished product. In
the near future there will be a few minor additions to the
software which will be discussed in the next paragraph.
Aside from these additions I will take sugestions from users
of the software on what they would like to see added or
changed. In the present revision [ver 2.16] only registered
outputs are supported. This will be changed in ver 2.17 and
latter versions.
The TiDE software will allow a design engineer to enter
a minimal amount of information about the actual device to
be used and then enter a description of what the state
machine should do by drawing the timing diagram on the
screen of the PC or PC clone.
b) Future Additions
1) Support for Abel
In the near future TiDE will ask you if you will be
using MMI's PALasm 2 or Data I/O's ABLE software. It will
then generate the proper file for use with your software.
2) Support for Cupl
Due to the fact that I have not seen as many customers
using the Assisted Technology CUPL software I will be
waiting to see the number of requests that I get for this
feature. If enough people want it I will do it.
3) Reduction of Boolean Equations
I had intended to include a boolean reduction program
for use with PALasm 2 but I now feel that it would be better
to release a working version of the program and then add the
reduction routine in a future release.
B. GETTING STARTED
1. Hardware Requirement
a) Minimum Required System
The minimum system that this software has been tested
on was a DATA GENERAL ONE laptop computer with 256 K of
memory. This system is an MS Dos machine with a few
exceptions. I feel that if it runs on this machine it
should run on any MS Dos computer. If you find an MS Dos
machine that this will not run on please contact me with the
details.
Due to the method used for drawing the wave forms you
do not need to have any graphics capability at all. The
program is small enough to only require a single floppy disk
to hold both the program and the files created by the
program. With these limited requirements it should be
possible to run TiDE on allmost any MS Dos computer.
b) Recomended Hardware
There is only one piece of hardware that would make a
nice addition and that is an IBM graphics printer. The
Epson printers and their clones will not work for screen
dumps of the timing diagram without the use of special
software such as Print Works by SoftStyle. The reason for
this is that the graphics on the screen are only the
extended character set of the IBM PC and are not really
graphics at all. On an Epson or equivalent the graphics
characters are not there and instead you will get italics
characters. This is only a limitation if you wish to get a
hardcopy of the screen while in the drawing mode.
2. Main Menu Commands
a) Naming the pins - F1
This is the first option on the main menu and it is
used to enter the mneumonics that you wish to assign to the
inputs and outputs of the device to be designed. To invoke
this Press the F1 key while the main menu is desplayed. This
is the first thing that must be done on any new design.
b) Entering the signal list order - F2
This option does not need to be used unless you wish to
have the signals shown in an order other than the pin number
order. When you use this option you have the ability to
have the same signal displayed as many times as you wish.
The only warning is that a signal that is showing in two or
more places on the screen should not be edited. You will
get very strange results if you try to do this. Even with
this precaution you may wish to display the same signal more
than once to allow you to compare the timing of this signal
to another.
c) Drawing the signals on the screen - F3
This is the fun part. Once you have entered the pin
names you may begin to draw the signals by using this
option. A menu of the available commands is located at the
bottom of the screen. This menu lists all of the keys that
may be used to enter data, edit signals, or control the
screen.
The first part that we will discuss is the method for
entering the data. The valid input keys for this are the
"X", "H", and the "L" keys. Upper or lower case will work.
The meaning of the keys are:
X : don't care - the signal is undefined at this point.
H : high -
on input signal - pin will be high during the next
rising edge of the clock.
on output signal - this signal is to go high after the
next rising edge of the clock if the
previous columns conditions are met.
L : low - same as for H except defines the low condition.
The character entered will be displayed directly above
the cursor after which the cursor will advance one position.
The four arrow keys will all move the cursor in the
indicated direction. The cursor may not be moved off of the
screen nor will it scroll the screen when it hits the top or
bottom. If you wish to view the next five signals press the
pgdn key on the cursor control keypad. To view the previous
five signals use the pgup key. Due to the fact that there
are seven signals displayed on the screen there will always
be a two signal overlap for continuity.
The last of the control keys are the ins and del keys
again located on the cursor control keypad. These keys will
allow you to insert a spot into a signal which can then be
changed to the proper value. The cursor should be placed
under the first location that is to be moved to the right to
make room for the new value. The del key will delete the
value directly above the cursor and move everything to the
right of the cursor left to fill the hole. The use of these
two keys will help when you wish to make a small change
after entering a long signal so as not to have to enter the
entire signal again.
d) Creating the PALasm 2 formated file - F4
After you have entered the timing diagram you are ready
to produce the text file which will contain the heading,
equations and the simulation in a PALasm 2 format. If you
follow all the steps carefully in your design you should not
have to use an editor on the file at all. It is usually
possible to generate a file which is complete and ready to
be assembled into the fuse pattern for your part.
When this section starts it will ask you for a file
name. At this point you should enter the name for the
PALasm 2 file. Standard convention dictates that the
extension to the file name should be ".PDS", this stands for
Pal Design Specification. Care should be taken here not to
enter a filename that is already being used, at present no
checking is done to insure that a file is not overwritten
when the new file is created. This is a feature that will
be added to a future version.
After you have entered the filename you will be asked
several questions. If you are familiar with PALasm 2 you
will recognize that each of these questions is for the
heading of the file. If you are just testing a portion of
your design and this will not be the final version of your
design you may just press the ENTER key and leave the
heading blank. The exception to this is the part type, if
you do not enter a part type the software will declare the
part as a PALXXXX in the text file. At this point the file
will not work with palasm and you will have to use an editor
to change the part type to a valid one. This can be used to
your advantage if you wish to get the equations and then go
back to decide which Pal you wish to use.
The last question will ask you if you are using a part
which has the capability of programmable output polarity.
If you answer this question yes the software will determine
if an output should be written active low or active high
based on which will require the least number of product
terms. If you are not using a part with programmable
polarity all equations will be written active low. An
example of a part with programmable output polarity is the
PAL16P8 vs. the PAL16L8. The P in the part number
designates that the part has programmable polarity. Many of
the new parts being done by MMI have the added feature of
programmable polarity.
e) How to exit to Dos and save your work - F5
When you have finished entering information or if you
are interrupted you may save your work and continue it at a
latter time. This will save all pin names and signal values
that have been entered up to this point. This will also
allow you to come back into the screen editor and change the
timing diagram if you find a problem in the PAL at a latter
date.
f) How to exit to Dos without saving your work -F6
I hope that you will not need this option but if you do
here it is. If you make a major mistake while editing your
design file and you decide that you would like to lose the
changes that have been made since the last save you may do
so by using this key. A check is made to insure that you
really want to do this as there is no turning back once it
is done.
C. SAMPLE DESIGNS
1. 4 bit counter
a) with reset
b) with set, reset, and load
2. 8 bit ring counter
a) with reset
b) with reset and hold
D. ADVANCED FEATURES
1. More than one state machine in a PAL
Due to the way that this software generates the
equations to implement your design it is possible to define
multiple independent state machines in the same device. In
order to do this all you will have to do is insure that the
seperate sections are not drawn under each other. This
means that at least one column of nothing but don't cares
must seperate the sections. You can use this method to
implement several different sections in the same device.
2. Extended simulation capability
When the simulation section of the output file is being
generated it works from the timing diagram. The only signal
lines that it looks at are the input signals and the control
signals such as output enable. By extending one of the
input signals such as a output enable type simulation will
continue.
3. Designing a continuous counter
In order to make a state machine that will loop back on
itself you will need to show the starting point for the loop
as the last column of the design. For examples of this and
other special features look at the sample files on this
disk. Files with an extension of ".SIG" are design examples
that you can use to experiment with.
E. LIMITATIONS
1. *** CAUTION ***
This section will be used to list bugs that have been
found and reported. I will try to keep this section of the
manual current. Since this is the first official release of
the program I do not have any reported bugs as yet.
F. Who to contact with problems
If you have a problem with the operation of this
software or if you decide that a feature needs to be added I
have a computer bulletin board which you may use to leave me
a comment. The phone # for the board is (513) 866-5157.
This board will also contain the latest version of this
software along with the manual, as well as having other
utility programs to help you in designing with MMI Pal
devices.
G. Credits
Author : Bill Hollon
Field Applications Engineer
Monolithic Memories Inc.
261 Trumpet Drive
Dayton, Ohio 45449
Concept and Ideas : Mike Wier
Regional Sales Manager
Monolithic Memories Inc.
Anyone who makes a contribution of a signifigant idea will
be added to this list. So send in any and all ideas for
improvement.
Thanks;
William R. Hollon
