Datasheet

78K0/Ix2 CHAPTER 16 SERIAL INTERFACE CSI11
R01UH0010EJ0500 Rev.5.00 550
Feb 28, 2012
Figure 16-1. Block Diagram of Serial Interface CSI11
88
Internal bus
Output
selector
Output latch
SO11/P37
Transmit buffer
register 11 (SOTB11)
Transmit data
controller
SI11/P36
Serial I/O shift
register 11 (SIO11)
SSI11
Output latch
(P37)
PM37
SO11
output
Transmit controller
Clock start/stop controller &
clock phase controller
INTCSI11
Output latch
(P35)
PM35
SCK11/P35
SSI11
Selector
f PRS /2
f
PRS /2
2
f PRS /2
3
f PRS /2
4
f PRS /2
5
f PRS /2
6
f PRS /2
7
(1) Transmit buffer register 11 (SOTB11)
This register sets the transmit data.
Transmission/reception is started by writing data to SOTB11 when bit 7 (CSIE11) and bit 6 (TRMD11) of serial
operation mode register 11 (CSIM11) is 1.
The data written to SOTB11 is converted from parallel data into serial data by serial I/O shift register 11, and output to
the serial output pin (SO11).
SOTB11 can be written or read by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Cautions 1. Do not access SOTB11 when CSOT11 = 1 (during serial communication).
2. In the slave mode, transmission/reception is started when data is written to SOTB11 with a low
level input to the SSI11 pin. For details on the transmission/reception operation, refer to 16.4.2
(2) Communication operation.