M16C80 Datasheet, PDF (323/358 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/80 SERIES

M16C/80 Group
32. Standard serial I/O mode
How frequency is identified
When "0016" data is received 16 times from a peripheral unit at a baud rate of 9,600 bps, the value of the
bit rate generator is set to match the operating frequency (2 - 20 MHz). The highest speed is taken from
the first 8 transmissions and the lowest from the last 8. These values are then used to calculate the bit
rate generator value for a baud rate of 9,600 bps.
Baud rate cannot be attained with some operating frequencies. Table 32.4 gives the operation frequency
and the baud rate that can be attained for.
Table 32.4 Operation frequency and the baud rate
Operation frequency Baud rate Baud rate Baud rate
(MHZ)
9,600bps 19,200bps 38,400bps
20MHz
√
16MHZ
√
12MHZ
√
11MHZ
√
10MHZ
√
8MHZ
√
7.3728MHZ
√
6MHZ
√
5MHZ
√
4.5MHZ
√
4.194304MHZ
√
4MHZ
√
3.58MHZ
√
3MHZ
√
2MHZ
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
√
–
√
√
√
√
–
–
√ ^{: Communications possible}
– : Communications not possible
Baud rate
57,600bps
√
√
√
√
√
√
√
–
–
√
–
–
√
–
–
Baud rate
115,200bps
√
–
–
–
–
–
–
–
–
–
–
–
–
–
–
Rev.1.00 Aug. 02, 2005 ^{Page 312} of 329
REJ09B0187-0100