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CPU and registers
I am a student informatics and my teacher asked uw to look up the following thing:
A (8086) CPU has 7 registers ..
IR PC SP R0 R1 R2 R3
The question was why they start with R1 afther SP in stead of staring
with R1 and ending with R4 ... if you know the answer you would help me
alot by explaining it to me ;-)
Sk
A (8086) CPU has 7 registers ..
IR PC SP R0 R1 R2 R3
The question was why they start with R1 afther SP in stead of staring
with R1 and ending with R4 ... if you know the answer you would help me
alot by explaining it to me ;-)
Sk
ASKER CERTIFIED SOLUTION
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AX, BX, CX, DX, SI, DI, IP, CS, DS, ES, SS, SP, flags
If you want to see the registers first hand get to DOS prompt and type:
DEBUG
R
Q
This will display registers for you.
-r
AX=0000 BX=0000 CX=0000 DX=0000 SP=FFEE BP=0000 SI=0000 DI=0000
DS=176E ES=176E SS=176E CS=176E IP=0100 NV UP EI PL NZ NA PO NC
176E:0100 7415 JZ 0117
-q
AX, BX General Purpose Registers
CX Counter Register/General Purpose register
DX I/O Pointer Register/General Purpose register
SI/DI Source and Destination Index registers for string moves and data arrays
CS:IP Code Segment/Instruction Pointer - what's executing
DS Data Segment, implied segment for most data ops
ES Extra Segment, Implied segment register for DI
SS:SP Stack Segment - stack pointer is here
BP Base Pointer, alternate stack
Flags Condition Code register. Internal processor state flags, zero, neg, etc.
Have no clue what CPU that your register model is with. It's unfamiliar and certainly NOT 8086! Have written ASM in 8080A, Z80, 80x86, 6502, 6800, 68000, SEL 32/55, Z8000, & DEC 11-780 and none of *them* match what your teacher says the model is.
M