CMP = Compare (16-Bits)
| Hex | Mnemonic | Cycles |
|---|---|---|
| D4 nn nn | CMP BA, #nnnn | 12 |
| D5 nn nn | CMP HL, #nnnn | 12 |
| D6 nn nn | CMP X, #nnnn | 12 |
| D7 nn nn | CMP Y, #nnnn | 12 |
| CF 6C nn nn | CMP SP, #nnnn | 16 |
| CF 18 | CMP BA, BA | 16 |
| CF 19 | CMP BA, HL | 16 |
| CF 1A | CMP BA, X | 16 |
| CF 1B | CMP BA, Y | 16 |
| CF 38 | CMP HL, BA | 16 |
| CF 39 | CMP HL, HL | 16 |
| CF 3A | CMP HL, X | 16 |
| CF 3B | CMP HL, Y | 16 |
| CF 5C | CMP SP, BA | 16 |
| CF 5D | CMP SP, HL | 16 |
Execute
#nnnn = Immediate unsigned 16-Bits
BA = Register BA: (B shl 8) or A
HL = Register HL: (H shl 8) or L
X = Register X
Y = Register Y
SP = Register SP (Stack Pointer)
; CMP Sc2, Sc
;
; Sc2 = Source 2
; Sc = Source
(discarded) = Sc2 - Sc
Description
"16-Bits Source 2" subtracts with "16-Bits Source", result is discarded.
This instruction is used to compare values.
Conditions
Zero: Set when result is 0
Carry: Set when result is < 0
Overflow: Set when result overflow 16-bits signed range (< -32768 OR > 32767)
Sign: Set when bit 15 of the result is 1
Examples
; BA = 0x2EF0
CMP BA, $1337
; BA = 0x2EF0
; 0x1BB9 (0x2EF0 - 0x1337 = 0x(0)1BB9)
; F = (Zero=0):(Carry=0):(Overflow=0):(Sign=0)
; HL = 0xBB7E
; BA = 0xCF12
CMP BA, HL
; HL = 0xBB7E
; BA = 0xCF12
; 0xEC6C (0xCF12 - 0xBB7E = 0x(1)EC6C)
; F = (Zero=0):(Carry=1):(Overflow=0):(Sign=1)