Fujitsu FR81S User Manual

CHAPTER 40: MULTI-FUNCTION SERIAL INTERFACE 

 

 

6. Operation of CSIO 

 

FUJITSU SEMICONDUCTOR LIMITED 

CHAPTER : MULTI-FUNCTION SERIAL INTERFACE 

FUJITSU SEMICONDUCTOR CONFIDENTIAL 

219 



 SPI Transfer (II) Timing Chart (When Serial Chip Select Pin Used) 

Figure 6-15 SPI Transfer (II) Timing Chart (When Serial Chip Select Pin Used) 

D1

D0

●Transmission 
operation

SCK

SOUT

TDRE

TDR_RW

TXE

SCS*B

●Reception 
operation

SIN

Sampling

RDRF

RDR RD

RXE

D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D4 D5 D6 D7

TBI

D1

D0

D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D4 D5 D6 D7

1

st

 byte

2

nd

 byte

＊C

*A: 

More than 4 machine cycles are necessary after writing to TDR for slave transmission

                 （MS=1, SCKE=0, SOE=1）
*B:

SCS output when MS=0, SCS input when MS=1

*C:      

D7 when SCR:MS=0

　

D0 of the third byte when it is SCR:MS=1 and TDRE is ”L”
D7 when it is SCR:MS=1 and TDRE is ”H”

*D:

Internal counter to be count transmission bytes

*A

2

TBYTE

2

1

0

Transmissions 
counter*D

Load

 

 

MN705-00010-1v0-E

1532