
CHAPTER 13 SERIAL INTERFACE UART0
User’s Manual U16228EJ2V0UD
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13.3 Registers Controlling Serial Interface UART0
Serial interface UART0 is controlled by the following five registers.
Asynchronous serial interface operation mode register 0 (ASIM0)
Asynchronous serial interface reception error status register 0 (ASIS0)
Baud rate generator control register 0 (BRGC0)
Port mode register 1 (PM1)
Port register 1 (P1)
(1) Asynchronous serial interface operation mode register 0 (ASIM0)
This 8-bit register controls the serial communication operations of serial interface UART0.
This register can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets this register to 01H.
Figure 13-2. Format of Asynchronous Serial Interface Operation Mode Register 0 (ASIM0) (1/2)
Address: FF70H After reset: 01H R/W
Symbol
<7>
<6>
<5>
4
3
2
1
0
ASIM0
POWER0
TXE0
RXE0
PS01
PS00
CL0
SL0
1
POWER0
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
Note 2
.
1
Enables operation of the internal operation clock.
TXE0
Enables/disables transmission
0
Disables transmission (synchronously resets the transmission circuit).
1
Enables transmission.
RXE0
Enables/disables reception
0
Disables reception (synchronously resets the reception circuit).
1
Enables reception.
Notes 1.
The input from the R
X
D0 pin is fixed to high level when POWER0 = 0.
2.
Asynchronous serial interface reception error status register 0 (ASIS0), transmit shift register 0 (TXS0),
and receive buffer register 0 (RXB0) are reset.