Chapter 14 Serial Interface Uart6; Functions Of Serial Interface Uart6 - NEC 78K0/KD1 Series User Manual

14.1 Functions of Serial Interface UART6

Serial interface UART6 has the following two modes.
(1) Operation stop mode
This mode is used when serial transfer is not executed and can enable a reduction in the power consumption.
For details, refer to 14.4.1 Operation stop mode.
(2) Asynchronous serial interface (UART) mode
This mode supports the LIN (Local Interconnect Network) bus. The functions of this mode are outlined below.
• Two-pin configuration
• Data length of transfer data can be selected from 7 or 8 bits.
• Dedicated internal 8-bit baud rate generator allowing any baud rate to be set
• Transmission and reception can be performed independently.
• Twelve operating clock inputs selectable
• MSB- or LSB-first transfer selectable
• Inverted transmission operation
• Tuning break field transmission from 13 to 20 bits
• More than 11 bits can be identified for tuning break field reception (SBF reception flag provided).
Cautions 1. The initial value of the T
a port pin.
2. The T D6 output inversion function inverts only the transmission side and not the reception
X
side. To use this function, the reception side must be ready for reception of inverted data (it
must be able to recognize a low-level start bit).
3. 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 T
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.
4. If data is continuously transmitted, the transfer rate from the stop bit to the next start bit is
extended two clocks. However, this does not affect the result of transfer because the
reception side initializes the timing when it has detected a start bit.
continuous transmission function if the interface is incorporated in LIN.
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CHAPTER 14 SERIAL INTERFACE UART6

T D6: Transmit data output pin
X
R B6: Receive data input pin
X
D6 pin is the high level. Exercise care when using the T
X
D6 pin also holds the value immediately before clock supply was
X
Preliminary User's Manual U16315EJ1V0UD
D6 pin as
X
Do not use the