Timing Of 3-Wire Variable-Length Serial I/O Mode (When Csib4 = 08H) - NEC V850/SB1 User Manual

(c) Transfer start
A serial transfer becomes possible when the following two conditions have been satisfied.
• The SIO4 operation control bit (CSIE4) = 1
• After a serial transfer, the internal serial clock is stopped.
Serial transfer starts when the following operation is performed after the above two conditions have been
satisfied.
• Transmit/transmit and receive mode (MODE4 = 0)
Transfer starts when writing to SIO4.
• Receive-only mode
Transfer starts when reading from SIO4.
Caution After data has been written to SIO4, transfer will not start even if the CSIE4 bit value is
set to 1.
Completion of the final-bit transfer automatically stops the serial transfer operation and sets the interrupt
request flag (INTCSI4).
Figure 10-61. Timing of 3-Wire Variable-Length Serial I/O Mode (When CSIB4 = 08H)
SCK4 (CMODE = 0)
SO4 (DMODE = 0)
Remark CSIB4 = 08H (CMODE = 0, DMODE = 0, DIR = 0, BSEL3 to BSEL0 = 1000)
430
CHAPTER 10 SERIAL INTERFACE FUNCTION
1 2
LSB
SI4
LSB
INTCSI4
User's Manual U13850EJ6V0UD
3 4 5 6 7
Transfer end
8
MSB
MSB