CHAPTER 11 SERIAL INTERFACE UART0 (
µ
PD78F0102H AND 78F0103H ONLY)
Preliminary User’s Manual U16846EJ1V0UD
213
(2) Communication
operation
(a) Format and waveform example of normal transmit/receive data
Figures 11-6 and 11-7 show the format and waveform example of the normal transmit/receive data.
Figure 11-6. Format of Normal UART Transmit/Receive Data
Start
bit
Parity
bit
D0
D1
D2
D3
D4
1 data frame
Character bits
D5
D6
D7
Stop 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 11-7. Example of Normal UART Transmit/Receive Data Waveform
1. Data length: 8 bits, Parity: Even parity, Stop bit: 1 bit, Communication data: 55H
1 data frame
Start
D0
D1
D2
D3
D4
D5
D6
D7
Parity
Stop
2. Data length: 7 bits, Parity: Odd parity, Stop bit: 2 bits, Communication data: 36H
1 data frame
Start
D0
D1
D2
D3
D4
D5
D6
Parity
Stop
Stop
3. Data length: 8 bits, Parity: None, Stop bit: 1 bit, Communication data: 87H
1 data frame
Start
D0
D1
D2
D3
D4
D5
D6
D7
Stop