Registers Controlling Serial Interface Uart0 - NEC 78K0 Series User Manual

14.3 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 signal generation sets this register to 01H.
Figure 14-2. Format of Asynchronous Serial Interface Operation Mode Register 0 (ASIM0) (1/2)
Address: FF70H After reset: 01H R/W
Symbol <7>
ASIM0 POWER0
POWER0
Note 1
0
1
TXE0
0
1
RXE0
0
1
Notes 1. The input from the R
2. Asynchronous serial interface reception error status register 0 (ASIS0), transmit shift register 0 (TXS0),
and receive buffer register 0 (RXB0) are reset.
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CHAPTER 14 SERIAL INTERFACE UART0
<6> <5>
TXE0 RXE0
Enables/disables operation of internal operation clock
Disables operation of the internal operation clock (fixes the clock to low level) and asynchronously
Note 2
resets the internal circuit .
Enables operation of the internal operation clock.
Disables transmission (synchronously resets the transmission circuit).
Enables transmission.
Disables reception (synchronously resets the reception circuit).
Enables reception.
D0 pin is fixed to high level when POWER0 = 0.
X
Preliminary User's Manual U17260EJ3V1UD
4 3
PS01 PS00 CL0
Enables/disables transmission
Enables/disables reception
2 1 0
SL0 1