Datasheet

CHAPTER 13 SERIAL INTERFACE UART0

User’s Manual U18698EJ1V0UD

317

13.3 Registers Controlling Serial Interface UART0

Serial interface UART0 is controlled by the following six 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 function register 1 (PF1)

• 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 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

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

XD0 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.