upd78f0114hgb-8es-a Renesas Electronics Corporation., upd78f0114hgb-8es-a Datasheet - Page 492

• Manufacturer Part Number: upd78f0114hgb-8es-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

492
Serial
Interface
UART0
Serial
Interface
UART6
Function
Baud rate error
Allowable baud
rate range
during reception
UART mode
TXB6: Transmit
buffer register 6
ASIM6:
Asynchronous
serial interface
operation mode
register 6
Details of
Function
Keep the baud rate error during transmission to within the permissible error range
at the reception destination.
Make sure that the baud rate error during reception satisfies the range shown in
(4) Permissible baud rate range during reception.
Make sure that the baud rate error during reception is within the permissible error
range, by using the calculation expression shown below.
The TXD6 output inversion function inverts only the transmission side and not the
reception side. To use this function, the reception side must be ready for
reception of inverted data.
If clock supply to serial interface UART6 is not stopped (e.g., in the HALT mode),
normal operation continues. If clock supply to serial interface UART6 is stopped
(e.g., in the STOP mode), each register stops operating, and holds the value
immediately before clock supply was stopped. The TXD6 pin also holds the value
immediately before clock supply was stopped and outputs it. However, the
operation is not guaranteed after clock supply is resumed. Therefore, reset the
circuit so that POWER6 = 0, RXE6 = 0, and TXE6 = 0.
If data is continuously transmitted, the communication timing from the stop bit to
the next start bit is extended two operating clocks of the macro. However, this
does not affect the result of communication because the reception side initializes
the timing when it has detected a start bit. Do not use the continuous
transmission function if UART6 is used in the LIN communication operation.
Do not write data to TXB6 when bit 1 (TXBF6) of asynchronous serial interface
transmission status register 6 (ASIF6) is 1.
Do not refresh (write the same value to) TXB6 by software during a
communication operation (when bit 7 (POWER6) and bit 6 (TXE6) of
asynchronous serial interface operation mode register 6 (ASIM6) are 1 or when bit
7 (POWER6) and bit 5 (RXE6) of ASIM6 are 1).
At startup, set POWER6 to 1 and then set TXE6 to 1. To stop the operation, clear
TXE6 to 0, and then clear POWER6 to 0.
At startup, set POWER6 to 1 and then set RXE6 to 1. To stop the operation, clear
RXE6 to 0, and then clear POWER6 to 0.
Set POWER6 to 1 and then set RXE6 to 1 while a high level is input to the RxD6
pin. If POWER6 is set to 1 and RXE6 is set to 1 while a low level is input,
reception is started.
Clear the TXE6 and RXE6 bits to 0 before rewriting the PS61, PS60, and CL6 bits. p. 272
Fix the PS61 and PS60 bits to 0 when the UART6 is used in the LIN
communication operation.
Make sure that TXE6 = 0 when rewriting the SL6 bit. Reception is always
performed with “the number of stop bits = 1”, and therefore, is not affected by the
set value of the SL6 bit.
Make sure that RXE6 = 0 when rewriting the ISRM6 bit.
APPENDIX D LIST OF CAUTIONS
User’s Manual U16961EJ4V0UD
Cautions
p. 260
p. 260
p. 262
p. 264
p. 264
p. 264
p. 270
p. 270
p. 272
p. 272
p. 272
p. 272
p. 272
p. 272
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