SynthBite16
A 16-Bit computer(C.I.S.C) with 38 Instructions, two addressing modes and a register stack!
Usage:
- Play around with the computer.
Clone into the repo and open the '.circ' with logisim-evolution
There are a couple of examples in thegit clone https://github.com/Harsha-vardhan-R/SynthBite16examplesdirectory in the cloned repo, mosty it will not be enough so to write your own program:
* Refer to theDocs.txtto see the Instructions and what exactly they do.
* compile the program with the assembler whose binary is provided with these commands.(if you want to compile it yourself just use g++ on main.cpp)(it is a single file program)
./Assembler* load the RAM in logisim with the output file from theAssembler.
* Reset all the registers in the computer with theCOMPUTER REBOOTbutton.
*** ALWAYS THE SIMULATION SHOULD START FROM LOW CLOCK VALUE!!! - Found Bugs?
- If you think you found a bug and can fix it, please try to fix it and send a PULL REQUEST.
- else raise an Issue so that anyone who s intrested can fix it.
Instruction set of the computer :
-OPERAND IS REQUIRED :
-DIRECT AND INDIRECT ADDRESSING
=> 1 X X X | 9 X X X -> LFA -> LOAD -> LOAD THE VALUE FROM THE ADDRESS INTO DR.
=> 2 X X X | A X X X -> STR -> STORE -> STORES THE PRESENT VALUE OF AC IN THE OPERAND ADDRESS.
=> 3 X X X | B X X X -> JMP -> JUMP_COND -> JUMP CONDITIONALLY TO THE GIVEN ADDRESS.
=> 4 X X X | C X X X -> CAL -> CALL -> CALL A SUBROUTINE.
=> 5 X X X | D X X X -> RET -> RETURN -> RETURN FROM A SUBROUTINE.
=> 6 X X X | E X X X -> LDI -> LOAD IMM -> LOAD IMMEDIATE VALUE INTO THE AC, (THE HIGHEST 4 BITS WILL BE FILLED WITH 0).
=> 7 X X X | F X X X -> SWP -> SWAP -> SWAPS THE VALUES OF AC AND THE OPERAND.
-OPERAND IS NOT REQUIRED : INSTRUCTION FORMAT 0-X-X-X OR 8-X-X-X
-INSTRUCTIONS MANIPULATING DATA :
-INSTRUCTIONS ON THE STACK :
=> 8 0 X X -> PSH -> PUSH ONTO THE STACK -> (STACK TOP <- DR, SP <- SP + 1)
=> 8 1 X X -> POP -> POP FROM THE STACK -> POP THE VALUE FROM THE STACK TOP AND PLACE IT IN THE OUT BUFFER REGISTER.
=> 8 2 X X -> ADS -> ADD THE TOP TWO ELEMENTS IN THE STACK -> (STACK TOP <- STACK TOP + STACK TOP AFTER A POP)
=> 8 3 X X -> SDS -> SUBTRACT ON THE STACK -> (STACK TOP <- STACK TOP - STACK TOP AFTER A POP)
=> 8 4 X X -> MDS -> MULTIPLY ON THE STACK -> (STACK TOP <- STACK TOP * STACK TOP AFTER A POP)
=> 8 5 X X -> DDS -> DIVIDE ON THE STACK -> (STACK TOP <- STACK TOP / STACK TOP AFTER A POP)
=> 8 6 X X -> LFS -> LOAD FROM STACK TOP -> (AC <- STACK TOP)
-INSTRUCTIONS ON ACCUMULATOR AND DATA REGISTER :
=> 0 0 X X -> LFD -> LOAD FROM DR(AC <- DR) -> LOAD THE VALUE OF THE DATA REGISTER INTO AC.
=> 0 1 X X -> LDC -> LOAD DATA COMPLIMENT(AC <- ~DR) -> LOAD THE COMPLIMENT OF THE VALUE OF DR INTO AC.
=> 0 2 X X -> ADD -> ADD(DR + AC) -> ADD THE VALUE OF DR AND AC AND STORE IT IN AC.
=> 0 3 X X -> MUL -> MULTIPLY(DR * AC) -> MULTIPLY THE VALUE OF DR WITH AC.
=> 0 4 X X -> SUB -> SUBTRACT(AC <- DR + (~AC + 1)) -> SUBTRACT AC FROM DR.
=> 0 5 X X -> DIV -> DIVIDE(AC <- REMAINDER OF AC/DR, QR <- AC/DR)-> DIVIDE AC WITH DR.
=> 0 6 X X -> CMP -> COMPARE THE VALUES OF DR AND AC -> WILL SET THREE BITS BASED ON THE COMPARISION(SMALLER, EQUAL, GREATER).
=> 0 7 X X -> AND -> BITWISE AND(AC <- AC && DR) -> BITWISE AND WITH AC.
=> 0 8 X X -> BOR -> BITWISE OR(AC <- AC || DR) -> BITWISE OR WITH AC.
=> 0 9 X X -> XOR -> BITWISE XOR(AC <- AC ^ DR) -> BITWISE XOR WITH AC.
=> 0 A X X -> SHR -> SHIFT AC TO RIGHT -> SHIFT THE AC VALUE TO THE RIGHT.
=> 0 B X X -> SHL -> SHIFT AC TO THE LEFT -> SHIFT THE AC VALUE TO THE LEFT.
=> 0 D X X -> RND -> RANDOM NUMBER IN AC -> LOAD A RANDOM NUMBER IN AC.
=> 0 E X X -> IBO -> INCREMENT BY ONE -> AC <= AC+1
-INSTRUCTIONS TO SET THE COMPARISION BITS :
=> 8 7 X X -> CSC -> COMPARISION STATUS BIT -> COMPARE REGISTER CARRY(SETS THE COMPARE REGISTER THE PRESENT VALUE OF THE CARRY FLIP FLOP)
=> 8 8 X X -> CSO -> COMPARISION STATUS BIT -> COMPARE REGISTER ONE(SETS THE COMPARE ONE WITHOUT CHECKING ANY OTHER STUFF)
=> 8 9 X X -> CSL -> COMPARISION STATUS BIT -> COMPARE REGISTER(LESSER)(COMPARE SET LESSER)
=> 8 A X X -> CSE -> COMPARISION STATUS BIT -> COMPARE REGISTER(EQUAL)
=> 8 B X X -> CSG -> COMPARISION STATUS BIT -> COMPARE REGISTER(GREATER)
-EXTRA
=> 0 C X X -> SSI -> SET SERIAL INPUT TO 1 -> SET THE SERIAL INPUTS FOR THE SHIFT OPERATIONS.(IT WILL BE 0 BY DEFAULT EVERY TIME)
=> 0 F X X -> HLT -> PROGRAM HALT -> HALT THE EXECUTIION.
-INSTRUCTIONS RELATED I/O :
=> 8 C X X -> INP -> LOAD THE VALUE FROM INPUT REGISTER INTO THE DATA REGISTER.
=> 8 D X X -> OUT -> PLACE THE VALUE OF AC IN THE OUPUT REGISTER.
=> 8 E X X -> IEN -> SET THE INTERRUPT ENABLE ON.
=> 8 F X X -> IEF -> SET THE INTERRUPT ENABLE OF.
*** ROM IS NOT WRITTEN FOR DIVISION AND DIVISION ON THE STACK. INTERRUPT NOT TESTED.