CHAPTER 10 SERIAL INTERFACE FUNCTION
User’s Manual U13850EJ4V0UM
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10.4.3 Operations
UARTn has the following two operation modes.
•
Operation stop mode
•
Asynchronous serial interface mode
(1) Operation stop mode
In this mode serial transfers are not performed, allowing reduction in power consumption.
When in operation stop mode, pins can be used as ordinary ports.
(a) Register settings
Operation stop mode settings are made via bits TxEn and RXEn of asynchronous serial interface mode
register n (ASIMn).
Figure 10-37. ASIMn Setting (Operation Stop Mode)
After reset: 00H
R/W
Address: FFFFF300H, FFFFF310H
7
6
5
4
3
2
1
0
ASIMn
TXEn
RXEn
PS1n
PS0n
CLn
SLn
ISRMn
0
(n = 0, 1)
TXEn
RXEn
Operation mode
RXDn/Pxx pin function
TXDn/Pxx pin function
0
0
Operation stop
Port function
Port function
Caution Do not switch the operation mode until after the current serial transmit/receive
operation has stopped.