Mitsubishi microcomputers
M16C / 6N0 / 6N1 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
141
(3) Clock-asynchronous serial I/O mode (compliant with the SIM interface)
The SIM interface is used for connecting the microcomputer with a memory card I/C or the like; adding
some extra settings in UART2 clock-asynchronous serial I/O mode allows the user to effect this function.
Table 1.16.8 shows the specifications of clock-asynchronous serial I/O mode (used for the SIM interface).
Note 1: "n" denotes the value 00
16 to FF
16
that is set to the UART2 bit rate generator.
Note 2: If an overrun error occurs, the UART2 receive buffer will have the next data written in. Note also that
the UART2 receive interrupt request bit is not set to "1".
Table 1.16.8. Specifications of clock-asynchronous serial I/O mode (compliant with the SIM interface)
Interrupt request
generation timing
Item
Specification
Transfer data format
One stop bit (bit 4 at address 01F816 = "0")
With the direct format chosen
Set parity to "even" (bit 5 and bit 6 at address 01F816 = "1" and "1" respectively)
Set data logic to "direct" (bit 6 at address 01FD16 = "0").
Set transfer format to LSB (bit 7 at address 01FC16 = "0").
With the inverse format chosen
Set parity to "odd" (bit 5 and bit 6 at address 01F816 = "0" and "1" respectively)
Set data logic to "inverse" (bit 6 at address 01FD16 = "1")
Set transfer format to MSB (bit 7 at address 01FC16 = "1")
Transfer clock
With the internal clock chosen (bit 3 at address 01F816 = "0") : fjSIO2 / 16 (n + 1) (Note 1) : j=2, 8, 32
(Do not set external clock)
Transmission / reception
control
Disable the CTS and RTS function (bit 4 at address 01FC16 = "1")
Other settings
Set transmission interrupt factor to "transmission completed" (bit 4 at address
01FD16 = "1")
Transmission start
condition
To start transmission, the following requirements must be met:
- Transmit enable bit (bit 0 at address 01FD16 = "1")
- Transmit buffer empty flag (bit 1 at address 01FD16 = "1")
Reception start condition
To start reception, the following requirements must be met:
- Reception enable bit (bit 2 at address 01FD16 = "1")
- Detection of a start bit
When transmitting
When data transmission from the UART2 transfer register is completed
(bit 4 at address 01FD16 = "1")
When receiving
When data transfer from the UART2 receive register to the UART2 receive
buffer register is completed
Error detection
Overrun error (see the specifications of clock-asynchronous serial I/O) (Note 2)
Framing error (see the specifications of clock-asynchronous serial I/O)
Parity error (see the specifications of clock-asynchronous serial I/O)
- On the transmission side, a parity error is detected by the level of input to
the RxD2 pin when a transmission interrupt occurs
The error sum flag (see the specifications of clock-asynchronous serial I/O)
- On the reception side, an "L" level is output from the TxD2 pin by use of the parity error
signal output function (bit 7 at address 01FD16 = "1") when a parity error is detected
The sleep mode select function is not available for UART2
Transfer data 8-bit UART mode (bit 2 through bit 0 at address 01F816 = "1012")
Clock Asynchronous Serial I/O (UART) Mode