upd78f0124m6gba1-8et Renesas Electronics Corporation., upd78f0124m6gba1-8et Datasheet - Page 254

• Manufacturer Part Number: upd78f0124m6gba1-8et
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

13.1 Functions of Serial Interface UART0
(1) Operation stop mode
(2) Asynchronous serial interface (UART) mode
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Serial interface UART0 has the following two modes.
This mode is used when serial communication is not executed and can enable a reduction in the power
consumption.
For details, see 13.4.1 Operation stop mode.
The functions of this mode are outlined below.
For details, see 13.4.2
generator.
• Two-pin configuration
• Length of communication data can be selected from 7 or 8 bits.
• Dedicated on-chip 5-bit baud rate generator allowing any baud rate to be set
• Transmission and reception can be performed independently.
• Four operating clock inputs selectable
• Fixed to LSB-first communication
Cautions 1. If clock supply to serial interface UART0 is not stopped (e.g., in the HALT mode), normal
2. Set POWER0 = 1 and then set TXE0 = 1 (transmission) or RXE0 = 1 (reception) to start
3. TXE0 and RXE0 are synchronized by the base clock (f
operation continues. If clock supply to serial interface UART0 is stopped (e.g., in the STOP
mode), each register stops operating, and holds the value immediately before clock supply
was stopped. The T
stopped and outputs it. However, the operation is not guaranteed after clock supply is
resumed. Therefore, reset the circuit so that POWER0 = 0, RXE0 = 0, and TXE0 = 0.
communication.
transmission or reception again, set TXE0 or RXE0 to 1 at least two clocks of base clock
after TXE0 or RXE0 has been cleared to 0. If TXE0 or RXE0 is set within two clocks of base
clock, the transmission circuit or reception circuit may not be initialized.
Asynchronous serial interface (UART) mode and 13.4.3
T
R
CHAPTER 13 SERIAL INTERFACE UART0
X
X
D0: Transmit data output pin
D0: Receive data input pin
X
D0 pin also holds the value immediately before clock supply was
User’s Manual U16315EJ3V1UD
XCLK0
) set by BRGC0. To enable
Dedicated baud rate