UPD750068GTA 查看數據表（PDF） - NEC => Renesas Technology

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产品描述 (功能)

生产厂家

UPD750068GTA

4 BIT SINGLE CHIP CMOS MICROCOMPUTERS

NEC => Renesas Technology 

µPD750064, 750066, 750068, 750064(A), 750066(A), 750068(A)

4.2 Setting Method of Stack Bank Select Register (SBS)

Switching between the Mk I mode and Mk II mode can be done by the stack bank select register (SBS). Figure

4-1 shows the format.

The SBS is set by a 4-bit memory manipulation instruction.

When using the Mk I mode, the SBS must be initialized to 100×BNote at the beginning of a program. When using

the Mk II mode, it must be initialized to 000×BNote.

Note Set the desired value in the × position.

Figure 4-1. Stack Bank Select Register Format

Address

F84H

3

2

1

0 Symbol

SBS3 SBS2 SBS1 SBS0 SBS

Stack area specification

0 0 Memory bank 0

0 1 Memory bank 1

Other than above setting prohibited

0 0 must be set in the bit 2 position.

Mode switching specification

0 Mk II mode

1 Mk I mode

Caution Since SBS. 3 is set to “1” after a RESET signal is generated, the CPU operates in the Mk I mode.

When executing an instruction in the Mk II mode, set SBS. 3 to “0” to select the Mk II mode.

Data Sheet U10165EJ2V0DS00

17

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