Table of Contents
Advertisement
12.3 Serial Interface 20 Control Registers
Serial interface 20 is controlled by the following registers.
• Serial operation mode register 20 (CSIM20)
• Asynchronous serial interface mode register 20 (ASIM20)
• Asynchronous serial interface status register 20 (ASIS20)
• Baud rate generator control register 20 (BRGC20)
(1)
Serial operation mode register 20 (CSIM20)
CSIM20 is used to make the settings related to 3-wire serial I/O mode.
CSIM20 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets CSIM20 to 00H.
Symbol
<7>
6
CSIM20
CSIE20 SSE20
CSIE20
0
Operation disabled
1
Operation enabled
SSE20
0
Not used
1
Used
DAP20
0
Outputs at the falling edge of SCK20
1
Outputs at the rising edge of SCK20
DIR20
0
MSB
1
LSB
CSCK20
0
External clock input to the SCK20 pin
1
Output of the dedicated baud rate generator
CKP20
0
Clock is low active, and SCK20 is at high level in the idle state
1
Clock is high active, and SCK20 is at low level in the idle state
Cautions 1. Bits 4 and 5 must be set to 0.
2. CSIM20 must be cleared to 00H if UART mode is selected.
CHAPTER 12 SERIAL INTERFACE 20
Figure 12-3. Format of Serial Operation Mode Register 20
5
4
3
2
0
0
DAP20 DIR20 CSCK20 CKP20
3-wire serial I/O mode operation control
SS20 pin selection
Port function
3-wire serial I/O mode data phase selection
3-wire serial I/O mode clock selection
3-wire serial I/O mode clock phase selection
User's Manual U15075EJ1V0UM00
1
0
Address
FF72H
Function of SS20/P22 pin
0
1
First-bit specification
After reset
R/W
00H
R/W
Communication status
Communication enabled
Communication enabled
Communication disabled
215
Advertisement
Table of Contents
