NEC PD750008 User Manual

Function:  (SP–1) <– MBS, (SP–2) <– RBS, SP <– SP–2

Saves the contents of the memory bank select register (MBS) and the register bank select register (RBS)

to the data memory location (stack) addressed by the stack pointer (SP), then decrements SP.

Function:  rp

L

 <– (SP), rp

H

 <– (SP+1), SP <– SP+2

Restores register pair rp (XA, HL, DE, BC) with the data at the data memory location (stack) addressed

by the stack pointer (SP), then increments SP.

The low-order part of a register pair (rp

L

:  A, L, E, C) is restored from the contents of (SP), and the high-

order part (rp

H

:  X, H, D, B) is restored with the contents of (SP+ ).

Function:  RBS <– (SP), MBS <– (SP+1), SP <– SP+2

Restores the register bank select register (RBS) and the memory bank select register (MBS) with the data

at the data memory location (stack) addressed by the stack pointer (SP), then increments SP.

Function:  IME (IPS.3) <– 1

Sets the interrupt master enable flag (bit 3 of the interrupt priority specification register) to 1 to enable

interrupts.  Whether to accept an interrupt is controlled with the corresponding interrupt enable flag.

Function:  IExxx <– 1     xxx = N

5

, N

2-0

Sets an interrupt enable flag (IExxx) to 1 to enable an interrupt.  (xxx = BT, CSI, T0, T1, W, 0, 1, 2, 4)

Function:  IME (IPS.3) <– 0

Resets the interrupt master enable flag (bit 3 of the interrupt priority specification register) to 0 to disable

all interrupts regardless of the states of the interrupt enable flags.