mc68000

MC68000: Divide by 3

I'm using shift operations to divide a long word in register D3 by three and storing the result in memory address specified by A2: Move.L D1, D2, D3, -(SP) CLR.L D5 MOVE.B #1, D4 Loop LSR.L D2, D3 ROXR.L #1,D5 BCS DONE SUBI.B #1, D2 BLT Loop CLR.B D4 DONE ...

MC 68000 Register question

please can someone tell how i will approach this Question..thanks The contents of selected registers and memory locations are specified as follows; D1:2; D3:$80A3; D4:$91EF; D4: $91EF; A2:$00008000; SP: $9000; $ABCDEF7 stored at $8000; $00124300 at $7FFC for the following independent segments of code statements, determine the modifie...

Shift operation on MC68000

I'm using shift operations to divide a long word in register D3 by three and storing the result in memory address specified by A2: MOVE.L D1, D2, D3, -(SP) CLR.L D5 MOVE.B #1, D4 Loop LSR.L D2, D3 ROXR.L #1,D5 BCS DONE SUBI.B #1, D2 BLT Loop CLR.B D4 ...

What does the ORG directive do in assembly code?

For reference, the code is for the motorola 68008. Say I have code such as the following: org 200 sequenceO: ds.b 5 sequenceN: ds.b 5 move.w #sequenceO, A0 move.w #sequenceN, A1 Am I correct in thinking that A0 will hold the value 200 and A1 the value 205? One of the exam questions in a past paper was: "What are the physical addres...

Programming Environment for a Motorola 68000 in Linux

Greetings all, I am taking a Structure and Application of Microcomputers course this semester and we're programming with the Motorola 68000 series CPU/board. The course syllabus suggests running something like Easy68K or Teesside Motorola 68000 Assembler/Emulator at home to test our programs. I told my prof I run x64 Linux and asked wh...

Where can I find assembler instruction specification info for the Motorola 68000?

I'm looking for information for machine language instruction encoding formats for the Motorola 68000 processor. I have used the The Motorola Mc68000 Microprocessor Family: Assembly Language, Interface Design, and System Design book for this before, but I no longer own a copy of the book. Does anyone know where I can find this informati...

audio to 8-bit text sample conversion

Hello community. I have an interesting question today. I need to convert some pokemon audio files to a list of 8-bit samples (0-255 values). I am writing an assembly routine on the MC6800 chipset that will require these sounds to be played. I plan on including an array with the 8-bit samples that the program will loop through when a fun...

random number generation

How to generate random numbers using assembly code in the range 1--4 ? ...