PD17012_15 Datasheet, PDF (34/320 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DIGITAL TUNING SYSTEM HARDWARE

µPD17012, 17P012
3.3 Stack Pointer (SP)
Figure 3-3 shows the configuration and function of the stack pointer.
The stack pointer is a 4-bit binary counter.
It specifies the address of an address stack register.
The value of the stack pointer can be directly read or written by using a register manipulation instruction.
Figure 3-3. Configuration and Function of Stack Pointer
Name
Stack pointer
SP
Flag symbol Address
b3 b2 b1 b0
0 S S S 01H
PPP
210
Read/
write
R/W
Specifies address of address stack register (ASR)
0 0 0 Address 0 (ASR0)
0 0 1 Address 1 (ASR1)
0 1 0 Address 2 (ASR2)
0 1 1 Address 3 (ASR3)
1 0 0 Address 4 (ASR4)
1 0 1 Address 5 (ASR5)
Fixed to “0”
Power-on
Clock stop
CE
0101
101
101
32
Data Sheet U10101EJ4V0DS