NEC 78K0 User Manual page 251

(2) Communication operation
(a) Format and waveform example of normal transmit/receive data
Figures 12-6 and 12-7 show the format and waveform example of the normal transmit/receive data.
Start
bit
One data frame consists of the following bits.
• Start bit ... 1 bit
• Character bits ... 7 or 8 bits (LSB first)
• Parity bit ... Even parity, odd parity, 0 parity, or no parity
• Stop bit ... 1 or 2 bits
The character bit length, parity, and stop bit length in one data frame are specified by asynchronous serial
interface operation mode register 0 (ASIM0).
Figure 12-7. Example of Normal UART Transmit/Receive Data Waveform
1. Data length: 8 bits, Parity: Even parity, Stop bit: 1 bit, Communication data: 55H
Start D0
2. Data length: 7 bits, Parity: Odd parity, Stop bit: 2 bits, Communication data: 36H
Start D0
3. Data length: 8 bits, Parity: None, Stop bit: 1 bit, Communication data: 87H
Start D0
CHAPTER 12 SERIAL INTERFACE UART0
Figure 12-6. Format of Normal UART Transmit/Receive Data
1 data frame
D0 D1 D2 D3
Character bits
1 data frame
D1 D2 D3
1 data frame
D1 D2 D3
1 data frame
D1 D2 D3
User's Manual U16227EJ2V0UD
Parity
D4 D5 D6 D7
bit
D4 D5 D6
D4 D5 D6
D4 D5 D6
Stop bit
D7 Parity Stop
Parity Stop Stop
D7 Stop
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