UPD78F0411GA-GAM-AX Datasheet, PDF (343/564 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 14 SERIAL INTERFACE UART6
(1) Receive buffer register 6 (RXB6)
This 8-bit register stores parallel data converted by receive shift register 6 (RXS6).
Each time 1 byte of data has been received, new receive data is transferred to this register from RXS6. If the
data length is set to 7 bits, data is transferred as follows.
• In LSB-first reception, the receive data is transferred to bits 0 to 6 of RXB6 and the MSB of RXB6 is always 0.
• In MSB-first reception, the receive data is transferred to bits 1 to 7 of RXB6 and the LSB of RXB6 is always 0.
If an overrun error (OVE6) occurs, the receive data is not transferred to RXB6.
RXB6 can be read by an 8-bit memory manipulation instruction. No data can be written to this register.
Reset signal generation sets this register to FFH.
(2) Receive shift register 6 (RXS6)
This register converts the serial data input to the RXD6 pin into parallel data.
RXS6 cannot be directly manipulated by a program.
(3) Transmit buffer register 6 (TXB6)
This buffer register is used to set transmit data. Transmission is started when data is written to TXB6.
This register can be read or written by an 8-bit memory manipulation instruction.
Reset signal generation sets this register to FFH.
Cautions 1. Do not write data to TXB6 when bit 1 (TXBF6) of asynchronous serial interface transmission
status register 6 (ASIF6) is 1.
2. Do not refresh (write the same value to) TXB6 by software during a communication
operation (when bits 7 and 6 (POWER6, TXE6) of asynchronous serial interface operation
mode register 6 (ASIM6) are 1 or when bits 7 and 5 (POWER6, RXE6) of ASIM6 are 1).
3. Set transmit data to TXB6 at least one base clock (fXCLK6) after setting TXE6 = 1.
(4) Transmit shift register 6 (TXS6)
This register transmits the data transferred from TXB6 from the TXD6 pin as serial data. Data is transferred from
TXB6 immediately after TXB6 is written for the first transmission, or immediately before INTST6 occurs after one
frame was transmitted for continuous transmission. Data is transferred from TXB6 and transmitted from the TXD6
pin at the falling edge of the base clock.
TXS6 cannot be directly manipulated by a program.
User’s Manual U18698EJ1V0UD
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