NEC PD754144 - Manual (Page 286)

CHAPTER 11 INSTRUCTION SET
286 User’s Manual U10676EJ3V0UM
PUSH rp
Function: (SP–1) ← rp H , (SP–2) ← rp L , SP ← SP–2
Saves the contents of register pair rp (XA, HL, DE, or BC) to the data memory (stack) addressed by the stack pointer
(SP), and then decrements the contents of the SP.
The higher 4 bits of the register pair (rp
H
, X, H, D, or B) are saved to the stack addressed by (SP–1), and the lower
4 bits (rp L : A, L, E, or C) are saved to the stack addressed by (SP–2).
PUSH BS
Function: (SP–1) ← MBS, (SP–2) ← RBS, SP ← SP–2
Saves the contents of the memory bank select register (MBS) and register bank select register (RBS) to the data
memory (stack) addressed by the stack pointer (SP), and then decrements the contents of the SP.
POP rp
Function: rp
L
← (SP), rp
H
← (SP+1), SP ← SP+2
Restores the contents of the data memory addressed by the stack pointer (SP) to register pair rp (XA, HL, DE,
or BC), and then decrements the contents of the stack pointer.
The contents of (SP) are restored to the higher 4 bits of the register pair (rp H , X, H, D, or B), and the contents of
(SP+1) are restored to the lower 4 bits (rp
L
: A, L, E, or C).
POP BS
Function: RBS ← (SP), MBS ← (SP+1), SP ← SP+2
Restores the contents of the data memory (stack) addressed by the stack pointer (SP) to the register bank select
register (RBS) and memory bank select register (MBS), and then increments the contents of the SP.