Skip to content

Latest commit

 

History

History
70 lines (53 loc) · 1.89 KB

PM_Opc_CMP16.md

File metadata and controls

70 lines (53 loc) · 1.89 KB

== 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)

« Back to Instruction set