PM_Opc_CMP8

== CMP = Compare (8-Bits) ==

Hex	Mnemonic	Cycles
30	CMP A, A	8
31	CMP A, B	8
32 nn	CMP A, #nn	8
33	CMP A, [HL]	8
34 nn	CMP A, [N+#nn]	12
35 nn nn	CMP A, [#nnnn]	16
36	CMP A, [X]	8
37	CMP A, [Y]	8
DB nn nn	CMP [N+#nn], #nn	16
CE 30 ss	CMP A, [X+#ss]	16
CE 31 ss	CMP A, [Y+#ss]	16
CE 32	CMP A, [X+L]	16
CE 33	CMP A, [Y+L]	16
CE 34	CMP [HL], A	16
CE 35 nn	CMP [HL], #nn	20
CE 36	CMP [HL], [X]	20
CE 37	CMP [HL], [Y]	20
CE BC nn	CMP B, #nn	12
CE BD nn	CMP L, #nn	12
CE BE nn	CMP H, #nn	12
CE BF nn	CMP N, #nn	12

Execute

#nn     = Immediate unsigned 8-Bits #ss     = Immediate signed 8-Bits A       = Register A B       = Register B N       = Register N [N+#nn] = Memory: (I shl 16) or (N shl 8) or #nn [HL]    = Memory: (I shl 16) or HL [X]     = Memory: (XI shl 16) or X [Y]     = Memory: (YI shl 16) or Y [#nnnn] = Memory: (I shl 16) or #nnnn [X+#ss] = Memory: (XI shl 16) or (X + #ss) [Y+#ss] = Memory: (YI shl 16) or (Y + #ss) [X+L]   = Memory: (XI shl 16) or (X + signed(L)) [Y+L]   = Memory: (YI shl 16) or (Y + signed(L))

; CMP Sc2, Sc ; ; Sc2 = Source 2 ; Sc  = Source

(discarded) = Sc2 - Sc

Description

"8-Bits Source 2" subtracts with "8-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 8-bits signed range (< -128 OR > 127)

Sign: Set when bit 7 of the result is 1

Examples

; A = 0x55 CMP`` ``A,`` ``$80 ; A = 0x55 ;     0xD5 (0x55 - 0x80 = 0x(1)D4) ; F = (Zero=0):(Carry=0):(Overflow=1):(Sign=1)

; B = 0x31 ; A = 0xCF CMP`` ``A,`` ``B ; B = 0x31 ; A = 0xCF ;     0x9E (0xCF - 0x31 = 0x(0)9E) ; F = (Zero=0):(Carry=0):(Overflow=0):(Sign=0)

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