UPD78F0411GA-GAM-AX Datasheet, PDF (318/564 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 13 SERIAL INTERFACE UART0
(1) Receive buffer register 0 (RXB0)
This 8-bit register stores parallel data converted by receive shift register 0 (RXS0).
Each time 1 byte of data has been received, new receive data is transferred to this register from receive shift
register 0 (RXS0).
If the data length is set to 7 bits the receive data is transferred to bits 0 to 6 of RXB0 and the MSB of RXB0 is
always 0.
If an overrun error (OVE0) occurs, the receive data is not transferred to RXB0.
RXB0 can be read by an 8-bit memory manipulation instruction. No data can be written to this register.
Reset signal generation and POWER0 = 0 set this register to FFH.
(2) Receive shift register 0 (RXS0)
This register converts the serial data input to the RXD0 pin into parallel data.
RXS0 cannot be directly manipulated by a program.
(3) Transmit shift register 0 (TXS0)
This register is used to set transmit data. Transmission is started when data is written to TXS0, and serial data is
transmitted from the TXD0 pins.
TXS0 can be written by an 8-bit memory manipulation instruction. This register cannot be read.
Reset signal generation, POWER0 = 0, and TXE0 = 0 set this register to FFH.
Cautions 1. Set transmit data to TXS0 at least one base clock (fXCLK0) after setting TXE0 = 1.
2. Do not write the next transmit data to TXS0 before the transmission completion interrupt
signal (INTST0) is generated.
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User’s Manual U18698EJ1V0UD