CHAPTER 11 SERIAL INTERFACE CSI10
Preliminary User’s Manual U19014EJ1V0UD
257
11.3 Registers Controlling Serial Interface CSI10
Serial interface CSI10 is controlled by the following four registers.
•
Serial operation mode register 10 (CSIM10)
•
Serial clock selection register 10 (CSIC10)
•
Port mode register 1 (PM1)
•
Port port register 1 (P1)
(1) Serial operation mode register 10 (CSIM10)
CSIM10 is used to select the operation mode and enable or disable operation.
CSIM10 can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation sets this register to 00H.
Figure 11-2. Format of Serial Operation Mode Register 10 (CSIM10)
Address: FF80H After reset: 00H R/W
Note 1
Symbol
<7>
6 5 4 3 2 1 0
CSIM10 CSIE10 TRMD10
0
DIR10
0
0
0
CSOT10
CSIE10
Operation control in 3-wire serial I/O mode
0
Disables
operation
Note 2
and asynchronously resets the internal circuit
Note 3
.
1
Enables
operation
TRMD10
Note 4
Transmit/receive
mode
control
0
Note 5
Receive mode (transmission disabled).
1
Transmit/receive
mode
DIR10
Note 6
First
bit
specification
0
MSB
1
LSB
CSOT10
Communication
status
flag
0
Communication is stopped.
1
Communication is in progress.
Notes 1.
Bit 0 is a read-only bit.
2.
To use P10/SCK10 and P12/SO10 as general-purpose ports, set CSIM10 in the default status (00H).
3.
Bit 0 (CSOT10) of CSIM10 and serial I/O shift register 10 (SIO10) are reset.
4.
Do not rewrite TRMD10 when CSOT10 = 1 (during serial communication).
5.
The SO10 output (see
(a)
in
Figure 11-1
) is fixed to the low level when TRMD10 is 0. Reception is
started when data is read from SIO10.
6.
Do not rewrite DIR10 when CSOT10 = 1 (during serial communication).
Caution Be sure to clear bits 1 to 3 and 5 to 0.
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