![](http://datasheet.mmic.net.cn/30000/M30800MC-XXXFP_datasheet_2359329/M30800MC-XXXFP_143.png)
Clock asynchronous serial I/O (UART) mode
Under
development
Preliminary Specifications REV.D
Specifications in this manual are tentative and subject to change.
Mitsubishi Microcomputers
M16C/80 group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
143
Item
Specification
Transfer data format
Character bit (transfer data): 7 bits, 8 bits, or 9 bits as selected
Start bit: 1 bit
Parity bit: Odd, even, or nothing as selected
Stop bit: 1 bit or 2 bits as selected
Transfer clock
When internal clock is selected (bit 3 at addresses 036016, 036816, 033816, 032816,
02F816 = “0”) : fi/16(n+1) (Note 1) fi = f1, f8, f32
When external clock is selected (bit 3 at addresses 036016, 036816, 033816, 032816,
02F816 =“1”) : fEXT/16(n+1)(Note 1) (Note 2)
Transmission/reception control
_______
CTS function/RTS function/CTS, RTS function chosen to be invalid
Transmission start condition
To start transmission, the following requirements must be met:
- Transmit enable bit (bit 0 at addresses 036516, 036D16, 033D16, 032D16,
02FD16) = “1”
- Transmit buffer empty flag (bit 1 at addresses 036516, 036D16, 033D16,
032D16, 02FD16) = “0”
_______
- When CTS function selected, CTS input level = “L”
- TxD output is selected by the corresponding function select register A, B
and C.
Reception start condition
To start reception, the following requirements must be met:
- Receive enable bit (bit 2 at addresses 036516, 036D16, 033D16, 032D16,
02FD16) = “1”
- Start bit detection
Interrupt request
When transmitting
generation timing
- Transmit interrupt cause select bits (bits 0,1 at address 037016, bit 4 at
address 033D16, 032D16, 02FD16) = “0”: Interrupts requested when data transfer
from UARTi transfer buffer register to UARTi transmit register is completed
- Transmit interrupt cause select bits (bits 0, 1 at address 037016, bit 4 at
address 033D16, 032D16, 02FD16) = “1”: Interrupts requested when data
transmission from UARTi transfer register is completed
When receiving
- Interrupts requested when data transfer from UARTi receive register to
UARTi receive buffer register is completed
(2) Clock asynchronous serial I/O (UART) mode
The UART mode allows transmitting and receiving data after setting the desired transfer rate and transfer
data format. Tables 1.18.1 and 1.18.2 list the specifications of the UART mode. Figure 1.18.1 shows the
UARTi transmit/receive mode register.
Table 1.18.1. Specifications of UART Mode (1)
Note 1: ‘n’ denotes the value 0016 to FF16 that is set to the UARTi bit rate generator.
Note 2: fEXT is input from the CLKi pin.