instruction_set.md

Instruction Set Reference

A-Instruction

Format: 0 v v v v v v v v v v v v v v v

Loads a 15-bit value into the A-register.

Example:

@5    ->  0000000000000101   // Load 5 into A
@100  ->  0000000001100100   // Load 100 into A

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C-Instruction

Format: 1 1 1 a c1 c2 c3 c4 c5 c6 d1 d2 d3 j1 j2 j3

ALU Control (a, c1-c6)

a	c1	c2	c3	c4	c5	c6	Computes
0	1	0	1	0	1	0	0
0	1	1	1	1	1	1	1
0	1	1	1	0	1	0	-1
0	0	0	1	1	0	0	D
0	1	1	0	0	0	0	A
1	1	1	0	0	0	0	M
0	0	0	1	1	1	1	!D
0	1	1	0	0	0	1	!A
0	0	0	1	1	1	0	-D
0	1	1	0	0	1	0	-A
0	0	1	1	1	1	1	D+1
0	1	1	0	1	1	1	A+1
0	0	0	1	1	1	0	D-1
0	1	1	0	0	1	0	A-1
0	0	0	0	0	1	0	D+A
0	0	1	0	0	1	1	D-A
0	0	0	0	1	1	1	A-D
0	0	0	0	0	0	0	D AND A
0	0	1	0	1	0	1	D OR A

Destination Bits (d1 d2 d3)

d1	d2	d3	Destination
0	0	0	No store
0	0	1	M (Memory[A])
0	1	0	D register
0	1	1	D and M
1	0	0	A register
1	0	1	A and M
1	1	0	A and D
1	1	1	A, D, and M

Jump Bits (j1 j2 j3)

j1	j2	j3	Jump Condition
0	0	0	No jump
0	0	1	Jump if > 0
0	1	0	Jump if = 0
0	1	1	Jump if >= 0
1	0	0	Jump if < 0
1	0	1	Jump if != 0
1	1	0	Jump if <= 0
1	1	1	Unconditional jump