VSASM Interpreter

HALTED -

Speed

Code Editor

Registers

Current Instruction

0 0

I/O Terminal

VSASM v1.0 Ready.

Memory (256 Bytes)

Machine Code

Stack Frame

Stack Top

Stack

Read/Fetch

Write

VSASM Reference Guide

Syntax	Opcode	Description
HALT	0b0	Stop program execution
JMP %reg	0b1	Copy value from register reg into register pc (Program Counter)
JMPIFNEG %reg	0b10	Copy value from register reg into register pc if ALU flag neg == 1
JMPIFZERO %reg	0b11	Copy value from register reg into register pc if ALU flag zero == 1
READ %reg	0b100	Read data from I/O device into register reg
SHOW %reg	0b101	Send data to I/O device from register reg
ADD %reg1 %reg2	0b110	Add numbers in registers reg1 and reg2 and store result in register reg1
SUB %reg1 %reg2	0b111	Subtract number in reg2 from number in reg1 and store result in reg1
NOT %reg	0b1000	Invert value in register reg
AND %reg1 %reg2	0b1001	Bitwise AND of reg1 and reg2, stored in reg1
OR %reg1 %reg2	0b1010	Bitwise OR of reg1 and reg2, stored in reg1
XOR %reg1 %reg2	0b1011	Bitwise XOR of reg1 and reg2, stored in reg1
MOV %reg1 %reg2	0b1100	Copy data from register reg2 to reg1
CMP %reg1 %reg2	0b1101	Subtract reg2 from reg1, discard result, update Z/N flags
PUT %reg byte	0b1xxxx	Put data byte into register reg
LOAD %reg addr	0b10xxxx	Load data from memory address addr into register reg
STORE %reg addr	0b11xxxx	Store data from register reg to memory address addr
LOADREG %reg1 %reg2	0b100xxxx	Load data from memory at address in reg2 into reg1
STOREREG %reg1 %reg2	0b101xxxx	Store data from reg1 into memory at address in reg2
OFFSET reg number	0b110xxxx	Put (BP - number) into register reg
LSHIFT %reg number	0b111xxxx	Shift reg left by number bits
RSHIFT %reg number	0b1000xxxx	Shift reg right by number bits