INSTRUCTION SET.md

INSTRUCTION REFERENCE

Instruction	Opcode	Format	Description
HALT	0x00	HALT	Ends Program
STR	0x01	STR addr rs	Store contents of register to memory
LD	0x02	LD rd addr	Load value from memory into register
JMP	0x03	JMP addr	Unconditional jump
MOV	0x04	MOV rs1 rs2	Copy contents of register rs2 into rs1
JMP_OFW	0x05	JMP_OFW addr	Jump if overflow flag set
JMP_ZRO	0x06	JMP_ZRO addr	Jump if zero flag set
JMP_NEG	0x07	JMP_NEG addr	Jump if negative flag set
JMP_ABV	0x08	JMP_ABV addr	Jump if both negative and zero flags are NOT set
ADD	0x09	ADD rd rs1 rs2	Add two registers
SUB	0x0A	SUB rd rs1 rs2	Subtract register 2 from 1
MUL	0x0B	MUL rd rs1 rs2	Multiply two registers
AND	0x0C	AND rd rs1 rs2	Logically AND two registers
OR	0x0D	OR rd rs1 rs2	Logically OR two registers
XOR	0x0E	XOR rd rs1 rs2	Logically XOR two registers
EQU	0x0F	EQU rd rs1 rs2	Compare two registers
DIV	0x10	DIV rd rs1 rs2	Divide rs1 by rs2
LI	0x11	LD rd val	Load immediate value
ADDI	0x12	ADDI rd rs1 val	Add register with immediate value
SUBI	0x13	SUBI rd rs1 val	Subtract immediate value from register
MULI	0x14	MULI rd rs1 val	Multiply register with immediate value
ANDI	0x15	ANDI rd rs1 val	AND register with immediate value
ORI	0x16	ORI rd rs1 val	OR register with immediate value
XORI	0x17	XORI rd rs1 val	XOR register with immediate value
EQUI	0x18	EQUI rd rs1 val	Compare register with immediate value
DIVI	0x19	DIVI rd rs1 val	Divide register by immediate value
CALL	0x1A	CALL addr	Record current value of PC and jump to start of subroutine
RET	0x1B	RET	Return to address of CALL function
NOP	0x1C	NOP	Do nothing for one cycle

ABOUT

Key Specifications:

• Data Width: 8-bit
• Address Space: 8-bit (255B)
• GP Registers: 16 8-bit general purpose registers
• Instruction Format: 1-3 bytes (opcode + operands)