Night Owl 25

home *** CD-ROM | disk | FTP | other *** search

/ Night Owl 25 / nopv25.iso / 040A / INTERCAL.ZIP / doc / chip.spec next >

Wrap

Text File | 1996-06-12 | 13.4 KB | 608 lines

The Intercal Machine Machine Language Specification File (c) 1990 Christian Brunschen, a. k. a. d89cb@efd.lth.se This file contains the specifications for the Machine / Assembly Language used by the Intercal Machine Microprocesor, which closely follows the definition of the Intercal Compiler Language as defined by Woods/Lyon in 1972. It also contains ideas as to the actual implementation, hard- or softwarewise, of the Processor Instruction Set in an actual environment. It should be noted that the Intercal Machine Microprocessor is the first actual RISC processor (RISC being, of course, the acronym for Ridiculous Instruction Set Computer). Overview of processor capabilities / requirements Schematic overview of processor I/O busses: +----------------\ /--------------+ _| \_/ |_ D +--- |_| D0 A04 |_| ---+ a | _| |_ | t | |_| D1 A05 |_| | a | _| |_ | | |_| D2 A06 |_| | b | _| |_ | u | |_| D3 A07 |_| | s ---+ _| |_ | | |_| D4 A08 |_| | 8 | _| |_ | A | |_| D5 A09 |_| | d b | _| |_ | d i | |_| D6 A10 |_| | r t | _| |_ | e s +--- |_| D7 A11 |_| | s _| |_ | s |_| DACK A12 |_| | _| |_ | |_| GND A13 |_| | _| _____ |_ | b |_| RESET A14 |_| +--- u _| ____ |_ | s |_| MEM/WRLD A15 |_| | _| _ |_ | 2 |_| R/W A16 |_| | 4 _| |_ | |_| CLK A17 |_| | b _| |_ | i |_| VCC A18 |_| | t _| |_ | s |_| ERROR A19 |_| | _| |_ | +--- |_| A00 A20 |_| | | _| |_ | | |_| A01 A21 |_| | | _| |_ | | |_| A02 A22 |_| | | _| |_ | | |_| A03 A23 |_| | | | | | | +-----------------------------------+ | | | | | +-------------------------------------------------+ The only signals that might require some explanation are probably _ R/W : When this signal is low, The processor is reading data from the databus. When it is high, the processor is driving the the databus. _____ RESET : When this signal goes low, the processor is reset, and starts reading incoming data from the databus, one byte each clock cycle, until the line goes high again, at which time the processor will resume execution of the program at memory location (Hex) 000000 (24 bits, remeber ?) ____ MEM/WRLD : _ Indicates the `target' or `source' (depending on the status of the R/W line) of the data bus, sort of like an additional address bit. If this line is low, the processor is communicating with the outside world. If it is high, the processor is talking to its memory. DACK : Data ACKnowledge. Used when the processor communicates with the outside world. Two cases: a) Processor Talking After the processor put the data on the databus, it will wait until the DACK has been raised, and then dropped again. Then it will put the next byte of data (if any) on the bus, or proceed to the next instruction. b) Processor listening The same procedure as above, but in the other direction : After the processor has read one byte of data, it quickly raises & drops the line, and then expects the next data item to be present. ERROR : Indicates the fact that an error condition has occurred somewhere in the program. The error number is present on the data bus. After the error number has ben read, the address of the next statement to be executed, had the eror not occurred, can be read in three consecutive bytes from the databus. Processor Memory Management Since the Intercal Language provides quite a few interesting ways to manipulate arrays, stash and retrieve data, etc, all of which operations require manipulations of memory, and it was the intention of this implementation to provide an instruction set which immediately makes the average Intercal programmer feel right at home, quite a few very complex instructions have been provided. Intercal Machine Language Reference Part Summary of instructions: ABG ABstain from Gerund ABL ABstain from Label ALA ALlocate Aray BAA Begin Array Allocation BIA Begin Indexing Array BIN BINary operator CAL CALculate DLD Data LoaD EAA End Array Allocation FRG FoRGet IDA InDex Array IGN IGNore INS INitiate Statement NEX NEXt OST Open STorage PCT PerCenTage qualifier POP POP PPA PoP Array pointers PSA PuSh Array pointers PSH PuSH RDO ReaD Out REG Reinstate Gerund REL Reinstate Label RMB ReMemBer RSM ReSuMe RTV ReTrieVe STS STaSh UNO UNary Operator WRI WRite In General Format: i i i i i p p s <optional arguments> where i = instruction field p = private field s = size field ABstain from Label ABL Label 0 1 1 1 1 0 0 0 Sets the abstain bit of instruction at Label ABstain from Gerund ABG mnm 0 1 1 1 1 1 0 0 Sets the abstain bit of all statements whosde main instruction is mnm Allocate Array ALA #num ALA .var ALA :var ALA , ALA ; ALA RES 0 0 0 1 1 p p s where p p specifies the source, 0 0 : immediate data <16 bits> 0 1 : Variable <variable specifier, 16 bits> 1 0 : Array, as pointed to by the Read Array Pointer 1 1 : the contents of the RES register Takes the ALA argument, multiplies it with the current contents of the Temproary Register, and puts the result in the Temporary Register. Begin Allocating Array BAA ,var BAA ;var 0 0 0 1 0 0 0 s array specifier, 16 bits jump offset, 16 bits Deallocates the memory block currently allocated to array `var', opens the Arrray Entry for array `var' for writing, and puts a pointer to the Array Entry in the Wite Array Data pointer register. If the array is being ignored, none of these things actually happen -- instead, the jump offset is added to the program counter. Begin Indexing Array BIA R ,var BIA W ,var BIA R ;var BIA W ;var 0 0 1 0 1 0 t s array specifier, 16 bits where t = type, 0 = Read or 1 = Write Sets the Read Array Data pointer to the address of the first array element, and the Read Array Dimension pointer to the first Dimension entry in the Array Table, thus preparing for further indexing. BINary operator BIN ~ Select BIN c/ Interleave, BIN $ aka Mingle 0 1 1 0 0 t 0 0 where t is the operation specifier: 0 : Select 1 : Interleave / Mingle The operation is performed on the OP1 and OP2 registers, and the result is placed in the RES register. CALculate CAL . CAL : CAL , CAL ; 0 1 0 1 0 0 0 s Puts the contents of the RES register in the memory location pointed to by the Write Array Data pointer Data LoaD DLD t #num DLD t .var DLD t :var DLD t , DLD t ; DLD t RES 0 1 0 0 t p p s where t = target register, 0 = OP1 or 1 = OP2 p p = source : 0 0 : Immediate data <16 bits> 0 1 : Variable <specifier, 16 bits> 1 0 : Array item (as indexed by the Read Array Data pointer) 1 1 : RES register Loads the target register with the contents of the source End Allocating Array EAA 0 0 1 0 0 0 0 0 Allocates a chunk of memory to the size of FoRGet FRG #num FRG .var FRG :var FRG , FRG ; FRG RES 1 0 0 0 0 p p s where p p = source : 0 0 : Immediate <16 bits> 0 1 : variable <specifier, 16 bits> 1 0 : array (as indexed by the Read Array Data pointer) 1 1 : RES register Pops source number of addresses from the stack, discarding them. InDex Array IDA R #num IDA W #num IDA R .var IDA W .var IDA R :var IDA W :var IDA R RES IDA W RES 0 0 1 1 t p p s where t = type, 0 = Read or 1 = Write p p = source : 0 0 : Immediate Data <16 bits> 0 1 : variable <specifier, 16 bits> 1 0 : ILLEGAL 1 1 : RES register Takes the Array Dimension (i.e, what the Array Dimension Pointer points to), adds (#num or RES) instances of it to the Array Data Pointer, and adds 2 to the Array Dimension Pointer. IGNore IGN .var IGN :var IGN ,var IGN ;var 1 0 1 0 1 0 0 s variable specifier, 16 bits Sets the ignore flag of the variable specified INitiate Statement INS mnm Label where `mnm' is one of the following 3-character mnemonics: ABS ABStain REI REInstate CAL CALculate NEX NEXt FRG FoRGet RES RESume STS STaSh RTV ReTrieVe IGN IGNore RMB ReMemBer WRI WRite In RDO ReaD Out 1 1 1 p p p p p 2 bytes : a o o o o o o o o o o o o o o o where p p p p p = major instruction opcode where a is the abstain bit of the instruction : set if this instruction is to be abstained from. The remaining 15 bits are the jump offset, which will be added to the program counter should the instruction be abstained from. It is presumed that no statement will result in code exceeding 32.767 bytes. NEXt NEX Label 0 1 1 0 1 0 0 0 Target Address, 24 bits Pushes the address of the next instruction on the return stack and puts the Target addres in the Program counter Open STorage OST .var Label OST :var Label OST ,var Label OST ;var Label 0 0 0 0 1 0 0 s variable/array specifier, 16 bits jump offset, 8 bits Trys to open the specified variable for writing. If it being ignored (i.e, its ignore flag is set) the jump offset is added to the program counter. If it is an array, the Write Array Data pointer is set to the address of the first element of the array, and the Write Array Dimension pointer to the first dimension entry in the Array Table. If it is a Variable, the Write Array Data pointer is set to the address of the Variable. PerCenTage qualifier PCT #num Label 0 0 0 0 0 0 0 0 0 c c c c c c c Jump offset, 16 bits where c c c c c c c is a 7 bit binary number between 0 and 100 Gets a random number in the range 0 .. 99, compares it to the percent chance and acts on the result: - if the random number is less than the percent chance, nothing is done - if it is equal or greater, the jump offset is added to the program counter POP POP 1 1 0 0 0 0 1 0 Gets the top item on the stack and puts it in the RES register -- 32 bits PoP Array pointers PPA 1 1 0 0 1 0 1 0 Retrieves the contents of the Read Array Data pointer from the stack PuSh Array pointers PSA 1 1 0 0 1 0 0 0 Pushes the contents of the Read Array Data pointer to an internal stack PuSH PSH 1 1 0 0 0 0 0 0 Pushes the RES register to the stack -- 32 bits ReaD Out RDO #num RDO .var RDO :var RDO , RDO ; RDO RES 1 0 1 1 1 p p s where p p = source: 0 0 : Immediate <16 bits> 0 1 : Variable <specifier, 16 bits> 1 0 : Array (as pointed to by the Read Array Data pointer) 1 1 : RES register Writes 2 or 4 bytes (16 or 32 bits) on the data bus REinstate Gerund REG mnm 0 1 1 1 0 1 0 0 operation specifier, 8 bits In this form, the hole program will be searched to find instructions of the specified type, and their abstain bits will be reset. REinstate Label REL Label 0 1 1 1 0 0 0 0 Label, 24 bits In this form, the instruction at the address of Label will have its abstain bit set/reset. ReMemBer RMB .var RMB :var RMB ,var RMB ;var 1 0 1 0 0 0 0 s variable specifier, 16 bits Clears the specified variable's ignore flag ReSuMe RSM #num RSM .var RSM :var RSM , RSM ; RSM RES 1 0 0 0 1 p p s where p p = source : 0 0 : Immediate <16 bits> 0 1 : variable <specifier, 16 bits> 1 0 : array (as indexed by the Read Array Data pointer) 1 1 : RES register Pops source number of addresses from the stack. If there are less than `source' items on the stack, the procesor is halted and an error signaled If no error occurs, the last popped address is NOT discarded, but instead placed in the Program counter. ReTrieVe RTV .var RTV :var RTV ,var RTV ;var 1 0 0 1 1 0 0 s Variable/Array Specifier, 16 bits Retrieves the latest stashed instance of the variable or array specified STaSh STS .var STS :var STS ,var STS ;var 1 0 0 1 0 0 0 s Variable/Array specifier, 16 bits Stashes the variable or array specified UNary Operator UNO & AND UNO V OR UNO V- XOR UNO ? XOR 0 1 0 1 1 t t s where t is the operation specifier: 00 : AND 01 : OR 10 : XOR 11 : Illegal The specified operation is performed on the RESult register, leaving it there. WRite In WRI . WRI : WRI , WRI ; 1 0 1 1 0 0 0 s Reads 2 or 4 bytes (16 or 32 bits) from the data bus and puts them in the variable pointed to by the Write Array Data pointer