PUSH = Push Register into Stack

Hex Mnemonic Cycles Regs stacked from top to bottom
A0 PUSH BA 16 B, A
A1 PUSH HL 16 H, L
A2 PUSH X 16 X(Hi), X(Lo)
A3 PUSH Y 16 Y(Hi), Y(Lo)
A4 PUSH N 12 N
A5 PUSH I 12 I
A6 PUSHX 16 XI, YI
A7 PUSH F 12 F
CF B0 PUSH A 12 A
CF B1 PUSH B 12 B
CF B2 PUSH L 12 L
CF B3 PUSH H 12 H
CF B8 PUSHA 48 B, A, H, L, X(Hi:Lo), Y(Hi:Lo), N
CF B9 PUSHAX 60 B, A, H, L, X(Hi:Lo), Y(Hi:Lo), N, I, XI, YI

Execute

A        = Register A
B        = Register B
L        = Register L
H        = Register H
N        = Register N
F        = Register F
I        = Register I
XI       = Register XI
YI       = Register YI
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)
    
; PUSH r16
;
; r16 = 16-Bits Register (BA, HL, X or Y)

SP = SP - 2
Memory[SP+1] = r16 SHR 8      ; (High Byte)
Memory[SP]   = r16 AND 0x00FF ; (Low Byte)
    
; PUSH r8
;
; r8  =  8-Bits Register (A, B, L, H, N, I and F)

SP = SP - 1
Memory[SP]   = r8
    
; PUSHX

SP = SP - 2
Memory[SP+1] = XI
Memory[SP]   = YI
    
; PUSHA

SP = SP - 9
Memory[SP+8] = B
Memory[SP+7] = A
Memory[SP+6] = H
Memory[SP+5] = L
Memory[SP+4] = X SHR 8      ; X(Hi)
Memory[SP+3] = X AND 0x00FF ; X(Lo)
Memory[SP+2] = Y SHR 8      ; Y(Hi)
Memory[SP+1] = Y AND 0x00FF ; Y(Lo)
Memory[SP]   = N
    
; PUSHAX

SP = SP - 12
Memory[SP+11] = B
Memory[SP+10] = A
Memory[SP+9]  = H
Memory[SP+8]  = L
Memory[SP+7]  = X SHR 8      ; X(Hi)
Memory[SP+6]  = X AND 0x00FF ; X(Lo)
Memory[SP+5]  = Y SHR 8      ; Y(Hi)
Memory[SP+4]  = Y AND 0x00FF ; Y(Lo)
Memory[SP+3]  = N
Memory[SP+2]  = I
Memory[SP+1]  = XI
Memory[SP]    = YI
    

Description

Push register(s) into the stack.

Conditions

None

Examples

; BA = 0x1337
; SP = 0x2000
PUSH BA
; BA = 0x1337
; SP = 0x1FFE
MOV A, 0x80
; BA = 0x1380
; SP = 0x1FFE
INC B
; BA = 0x1480
; SP = 0x1FFE
POP BA
; BA = 0x1337
; SP = 0x2000
    

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