Specifications

Serial Communications (82050)
Baud Rate
The ACC includes an internal baud rate generator to divide the
18.432 MHz reference frequency down to a value equal to 16 times
the baud rate. The divisor for the reference frequency is a 16-bit
integer programmed into the LSB and MSB of the Divisor Latch. The
relationship between the baud rate and the count is as follows:
Divisor = 18.432 x 10
6
/(160 x Baud Rate)
Table 11-4 lists the divisor to be used for the more popular baud rates.
It also shows the percent error, which is based on the difference
between the exact divisor for a specified baud rate and the divisor
obtainable with a 16-bit integer format. To guarantee proper
operation, the percent error should never be greater than four.
Table 11-4
ACC Baud Rate Divisors.
Baud Rate Divisor Percent Error
(dec/hex)
50 2304/1440 0
75 1536/0960 0
150 768/0480 0
300 384/0240 0
600 192/0120 0
1200 96/0060 0
1800 64/0040 0
2000 58/003A 0.69
2400 48/0030 0
3600 32/0020 0
4800 24/0018 0
7200 16/0010 0
9600 12/000C 0
19200 6/0006 0
38400 3/0003 0
56000 2/0002 2.86
11-22