NEC PD750008 User Manual
292
µPD750008 USER'S MANUAL
Remark "Function" in this section is applicable to the µPD750008 whose program counter consists of
13 bits (addr = 0000H to 1FFFH).
However, this is also applicable to the µPD750004 whose program counter consists of 12
bits (addr = 0000H to 0FFFH),the µPD750006 whose program counter consists of 13 bits
(addr = 0000H to 17FFH),and the µPD75P0016 whose program counter consists of 14 bits
(addr = 0000H to 3FFFH).
RETI
Function:
For the µPD750008
[Mk I mode]
PC
11-8
<– (SP), MBE, RBE, 0, PC
12
<– (SP+1)
PC
3-0
<– (SP+2)
PC
7-4
<– (SP+3)
PSW
L
<– (SP+4), PSW
H
<– (SP+5)
SP <– SP+6
[Mk II mode]
PC
11-8
<– (SP), 0, 0, 0, PC
12
<– (SP+1)
PC
3-0
<– (SP+2)
PC
7-4
<– (SP+3),
PSW
L
<– (SP+4), PSW
H
<– (SP+5)
SP <– SP+6
Restores the program counter (PC) and program status word with the data at the data memory location
(stack) addressed by the stack pointer (SP), then increments the contents of SP.
This instruction is used when control is returned from an interrupt service routine.
Remark "Function" in this section is applicable to the µPD750008 whose program counter consists of
13 bits (addr = 0000H to 1FFFH).
However, this is also applicable to the µPD750004 whose program counter consists of 12
bits (addr = 0000H to 0FFFH), the µPD750006 whose program counter consists of 13 bits
(addr = 0000H to 17FFH), and the µPD75P0016 whose program counter consists of 14 bits
(addr = 0000H to 3FFFH).
PUSH rp
Function: (SP–1) <– rp
H
, (SP–2) <– rp
L
, SP <– SP–2
Saves the contents of register pair rp (XA, HL, DE, BC) to the data memory location (stack) addressed by
the stack pointer (SP), then decrements SP.
The high-order part of a register pair (rp
H
: X, H, D, B) is saved to the stack location addressed by (SP–
1), and the low-order part (rp
L
: A, L, E, C) is saved to the stack location addressed by (SP–2).
I/II