Fox32 instructions
This file describes every fox32 instruction in detail. For a general
description of the fox32 CPU and instruction encoding details, see cpu.md.
Arithmetic instructions
ADD: add
SUB: subtract
INC: increment (add 1/2/4/8)
DEC: decrement (subtract
1/2/4/8)
CMP: compare
AND: bitwise AND
OR: bitwise OR
NOT: bitwise NOT
XOR: bitwise XOR
BSE: bit set
BCL: bit clear
BTS: test if bit set
SLA: shift left
SRA: shift right
arithmetic (with sign extension)
SRL: shift right
logical (with zero extension)
ROL: rotate left
ROR: rotate right
MUL: multiply (unsigned)
IMUL: multiply (signed)
DIV: divide (unsigned)
IDIV: divide (signed)
REM: calculate
remainder of division (unsigned)
IREM: remainder (signed)
NOP: no operation
MOV: move value
MOVZ:
move value and clear upper bits in target register
RTA:
calculate address relative to instruction pointer
Stack instructions
PUSH: push value to stack
POP: pop value from stack
Control flow instructions
JMP: absolute jump
RJMP: relative jump
LOOP: absolute loop
RLOOP: relative loop
CALL: absolute call
RCALL: relative call
RET: return from function
RETI: return from interrupt
ISE: set interrupt enable
flag
ICL: clear interrupt enable
flag
BRK: debug breakpoint
INT: raise interrupt
HALT: halt CPU
MMU instructions
MSE: set MMU enable flag
MCL: clear MMU enable flag
FLP: flush page from TLB
TLB: flush TLB and
set page directory pointer
I/O instructions
IN: get input from I/O bus
OUT: output on I/O bus