Question

I am trying to understand the specs, but fail to understand the first line of the example given:

SET A, 0x30              ; 7c01 0030

Here is what I understood from the specs:

• the first word (7c01) fully defines the instruction
• the operator is 0x1 which is the command SET a, b
• b = 111100 = 0x3C (when I convert into Hex) = literal value 0x3C
• a = 000000 = register A

So I understand the instruction as SET A, 0x3C

Can anyone advise where I go wrong?

Answer 1

Ah ok from the comments I finally got my answer.

You are missing the “Values” section from the spec, there it says:

Values:
....
0x1f: next word (literal)

So we have:

0x7c01 = 0111110000000001

0001 = SET
000000 = register A
011111 = 1F -> next word -> [PC++]

Next word is 0x0030… voilà.