NEC PD75P402, PD75402A user manual Register setting, Csie C0I WUP CSIM3 CSIM1 Csim

Models: PD75402A PD75P402

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CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS

5.5.4Operation-Halted Mode

The operation-halted mode is used when no serial transfer is performed, allowing power dissipation to be reduced.

In this mode, the shift register does not perform shift operations and can be used as an ordinary 8-bit register. When the RESET signal is input the operation-halted mode is set. The P02/SO/SB0 and P03/SI pins are fixed as input ports. P01/SCK can be used as an input port depending on the setting of the serial operating mode register.

(1) Register setting

Operation-halted mode setting is performed by the serial operating mode register (CSIM) (see 5.5.3 (1)“Serial operating mode register” for full details of CSIM).

CSIM is manipulated by 8-bit memory manipulation instructions, but bit manipulation of CSIE is also possible. Manipulation is also possible using bit names.

Reset input clears this register to 00H.

The shaded area indicates bits used in the operation-halted mode.

Address

FE0H

7

6

5

4

3

2

1

0

Symbol

CSIE

C0I

WUP

0

CSIM3

0

CSIM1

0

CSIM

 

 

 

 

 

 

 

 

 

Serial Clock Celection Bit (W)*

Serial Interface Operating Mode Selection Bit (W)

Wake-up Function Specification Bit (w)

Match Signal from Address Comparator (R)

Serial Interface Operation Enable/Disable Specification Bit (W)

*Allow selection of P01/SCK pin status.

Remarks (R) Read only

(W)Write only

Serial interface operation enable/disable specification bit (W)

 

 

Shift Register

Serial Clock

IRQCSI Flag

SO/SB0 & SI Pins

 

 

Operation

Counter

 

 

 

 

 

 

 

 

 

 

CSIE

0

Shift operation

Cleared

Retained

Port o function only

disabled

 

 

 

 

 

 

 

 

 

 

 

83

Page 94
Image 94
NEC PD75P402, PD75402A user manual Register setting, Csie C0I WUP CSIM3 CSIM1 Csim