CHAPTER 14 SERIAL INTERFACE UART6
Preliminary User’s Manual U16315EJ1V0UD
283
14.4 Operation of Serial Interface UART6
This section explains the two modes of serial interface UART6.
14.4.1 Operation stop mode
In this mode, serial transfer cannot be executed; therefore, the power consumption can be reduced. In addition,
the pins can be used as ordinary port pins in this mode.
(1) Register setting
The operation stop mode is set by asynchronous serial interface operation mode register 6 (ASIM6).
ASIM6 can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets this register to 01H.
Remark
ASIM6 can be refreshed (the same value is written) by software during a communication operation
(when bit 7 (POWER6) and bit 6 (TXE6) of ASIM6 = 1 or bit 7 (POWER6) and bit 5 (RXE6) of ASIM6
= 1).
Address: FF50H After reset: 01H R/W
Symbol
7
6
5
4
3
2
1
0
ASIM6
POWER6
TXE6
RXE6
PS61
PS60
CL
SL6
ISRM6
POWER6
Enables/disables operation of internal operation clock
0
Note 1
Disables operation of the internal operation clock (fixes the clock to low level) and asynchronously
resets the internal circuit.
1
Note 2
Enables operation of the internal operation clock.
TXE6
Enables/disables transmission
0
Disables transmission operation (synchronously resets the transmission circuit).
1
Enables transmission
RXE6
Enables/disables reception
0
Disables reception (synchronously resets the reception circuit).
1
Enables reception
Notes 1.
The output of the T
X
D6 pin goes high and the input from the R
X
D6 pin is fixed to the high level when
POWER6 = 0.
2.
Operation of the internal operation clock is enabled at the second input clock after 1 is written to the
POWER6 bit.
Cautions 1. At startup, set POWER6 to 1 and then set TXE6 to 1. Clear TXE6 to 0 first, and then clear
POWER6 to 0.
2. At startup, set POWER6 to 1 and then set RXE6 to 1. Clear RXE6 to 0 first, and then clear
POWER6 to 0.