Table of Contents
Advertisement
8.3.4 Basic operation
(1) Transfer format
The CSI performs interfacing by using three lines: one clock line and two data lines.
Serial transfer is started by executing an instruction that writes transfer data to the SIOn register.
During transmission, the data is output from the SOn pin in synchronization with the falling edge of SCKn.
During reception, the data input to the SIn pin is latched in synchronization with the rising of SCKn.
SCKn stops when the serial clock counter overflows (at the rising edge of the 8th count), and SCKn remains
high until the next data transmission or reception is started. At the same time, a transmission/reception
completion interrupt (INTCSI) is generated.
Caution
If CTXE is changed from 0 to 1 after the transmit data is sent to the SIOn registers, serial
transfer will not begin.
Remark n = 0 to 3
SCKn
SIn
SOn
CSOTn bit
INTCSIn interrupt
Remark n = 0 to 3
224
CHAPTER 8 SERIAL INTERFACE FUNCTION
Input data latched
1
2
3
4
5
DI7 DI6 DI5 DI4 DI3 DI2 DI1 DI0
DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0
Transfer starts in synchronization with falling of SCKn
Execution of SIOn write instruction
User's Manual U11969EJ3V0UM00
6
7
8
Serial transmission/
reception completion
interrupt occurs
Advertisement
Table of Contents
