Setting Of Stack Bank Selection (Sbs) Register - NEC uPD75P3116 Datasheet

4.2 Setting of Stack Bank Selection (SBS) Register

Use the stack bank selection register to switch between the Mk I mode and Mk II mode. Figure 4-1 shows the format
of the stack bank selection register.
The stack bank selection register is set using a 4-bit memory manipulation instruction. When using the Mk I mode, be
sure to initialize the stack bank selection register to 100×B
be sure to initialize it to 000×B
Note Set the desired value for ×.
Address 3 2 1
F84H SBS3 SBS2 SBS1 SBS0
Caution SBS3 is set to 1 after RESET input, and consequently the CPU operates in the Mk I mode. When using
instructions for the Mk II mode, set SBS3 to 0 and set the Mk II mode before using the instructions.
Note at the beginning of the program. When using the Mk II mode,
Note .
Figure 4-1. Format of Stack Bank Selection Register
0 Symbol
SBS
Stack area specification
0 0 Memory bank 0
0 1 Memory bank 1
1 0 Setting prohibited
1 1
0 Be sure to enter "0" for bit 2.
Mode selection specification
0 Mk II mode
1 Mk I mode
Data Sheet U11369EJ3V0DS
µ PD75P3116
15