NEC PD750008 User Manual
Page 311
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CHAPTER 11 INSTRUCTION SET
RET
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), SP <– SP+4
[Mk II mode]
PC
11-8
<– (SP), x, x, x, PC
12
<– (SP+1)
PC
3-0
<– (SP+2), PC
7-4
<– (SP+3)
x, x, MBE, RBE <– (SP+4)
SP <– SP+6
Restores the program counter (PC), memory bank enable flag (MBE), and register bank enable flag (RBE)
with the data at the data memory location (stack) addressed by the stack pointer (SP), then increments the
contents of SP.
Caution The program status word (PSW) is not restored except MBE and RBE.
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).
RETS
Function: For the µPD750008
[Mk I mode]
PC
11-8
<– (SP)
MBE, 0, 0, PC
12
<– (SP+1)
PC
3-0
<– (SP+2), PC
7-4
<– (SP+3), SP <– SP+4
Then skip unconditionally
[Mk II mode]
PC
11-8
<– (SP), 0, 0, 0, PC
12
<– (SP+1)
PC
3-0
<– (SP+2), PC
7-4
<– (SP+3)
x, x, MBE, RBE <– (SP+4)
SP <– SP+6
Then skip unconditionally
Restores the program counter (PC), memory bank enable flag (MBE), and register bank enable flag (RBE)
with the data at the data memory location (stack) addressed by the stack pointer (SP), then skips unconditionally
after incrementing the contents of SP.
Caution The program status word (PSW) is not restored except MBE and RBE.
I/II
I/II