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