SERIAL I/O
11.1 Overview
11.1 Overview
Serial I/O consists of 3 channels: UART0, UART1 and UART2. They each have a transfer clock generating
timer for the exclusive use of them and can operate independently.
UARTi (i = 0 to 2) has the following 2 operating modes:
(1) Clock synchronous serial I/O mode
Transmitter and receiver use the same clock as the transfer clock. Transfer data has a length of 8
bits.
(2) Clock asynchronous serial I/O (UART) mode
Transfer rate and transfer data format can arbitrarily be set. The user can select one transfer data
length from the following: 7 bits, 8 bits, and 9 bits.
Figure 11.1.1 shows the transfer data formats in each operating mode.
ꢀꢀClock synchronous serial I/O mode
ꢀꢀUART mode
Transfer data length of 8 bits (LSB first)
Transfer data length of 8 bits (MSB first)
Transfer data length of 7 bits
Transfer data length of 8 bits
Transfer data length of 9 bits
Fig. 11.1.1 Transfer data formats in each operating mode
7905 Group User’s Manual Rev.1.0
11-2
RENESAS [ RENESAS TECHNOLOGY CORP ]
