CHAPTER 13 SERIAL INTERFACE CSI10
Preliminary User’s Manual U16846EJ1V0UD
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(2) Communication
operation
In the 3-wire serial I/O mode, data is transmitted or received in 8-bit units. Each bit of the data is transmitted or
received in synchronization with the serial clock.
Data can be transmitted or received if bit 6 (TRMD10) of serial operation mode register 10 (CSIM10) is 1.
Transmission/reception is started when a value is written to transmit buffer register 10 (SOTB10). In addition,
data can be received when bit 6 (TRMD10) of serial operation mode register 10 (CSIM10) is 0.
Reception is started when data is read from serial I/O shift register 10 (SIO10).
After communication has been started, bit 0 (CSOT10) of CSIM10 is set to 1. When communication of 8-bit data
has been completed, a communication completion interrupt request flag (CSIIF10) is set, and CSOT10 is cleared
to 0. Then the next communication is enabled.
Caution Do not access the control register and data register when CSOT10 = 1 (during serial
communication).
Figure 13-5. Timing in 3-Wire Serial I/O Mode (1/2)
(1) Transmission/reception timing (Type 1; TRMD10 = 1, DIR10 = 0, CKP10 = 0, DAP10 = 0)
AAH
ABH
56H
ADH
5AH
B5H
6AH
D5H
55H (communication data)
55H is written to SOTB10.
SCK10
SOTB10
SIO10
CSOT10
CSIIF10
SO10
SI10 (receive AAH)
Read/write trigger
INTCSI10