CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS

(a)Serial operating mode register (CSIM)

When the 3-wire serial I/O mode is used, CSIM is set as shown below (see 5.5.3 (1) “Serial operating mode

register” for full details of CSIM).

CSIM is manipulated by 8-bit memory manipulation instructions. Bit manipulation of bits 7, 6 and 5 is also possible.

Reset input clears the CSIM register to 00H.

The shaded area indicates bits used in the 3-wire serial I/O mode.

Address

FE0H

7

6

5

4

3

2

1

0

Symbol

CSIE

C0I

WUP

0

CSIM3

0

CSIM1

0

CSIM

 

 

 

 

 

 

 

 

 

Serial Clock Selection 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)

Remarks (R) Read only

(W)Write only

Serial clock selection bit (W)

 

 

 

Serial Clock

 

 

 

 

 

CSIM1

 

 

 

 

 

 

SCK Pin Mode

 

 

3-Wire Serial I/O Mode

 

SBI Mode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

Input clock to

SCK

pin from off chip

 

 

Input

 

 

 

 

 

 

 

 

 

 

 

1

 

fXX/24 (262 kHz)

 

 

 

Output

 

 

 

 

 

 

 

 

 

 

Remarks Figuer in (

) apply to fXX = 4.19 MHz operation

 

 

 

 

Serial interface operating mode selection bit (W)

CSIM3

Operating Mode

Shift Register Bit Order

SO Pin Function

Si Pin Function

 

 

 

 

 

0

3-wire serial I/O

SIO 7 to 0 XA

SO/P02

SI/P03 (Input)

mode

(MSB-fist transfer)

(CMOS Output)

 

 

 

 

 

 

 

Wake-up function specification bit (W)

WUP

0 IRQCSI set at end of every serial transfer.

85

Page 96
Image 96
NEC PD75P402, PD75402A user manual Remarks Figuer Apply to fXX = 4.19 MHz operation