Intel 386 Computer Hardware User Manual


 
Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL
13-20
13.3.4 SSIO Baud-rate Control Register (SSIOBAUD)
Use SSIOBAUD to enable the baud-rate generator and determine the baud-rate generator’s sev-
en-bit down counter’s reload value (BV).
Figure 13-18. SSIO Baud-rate Control Register (SSIOBAUD)
SSIO Baud-rate Control
SSIOBAUD
(read/write)
Expanded Addr:
ISA Addr:
Reset State:
F484H
00H
7 0
BEN BV6 BV5 BV4 BV3 BV2 BV1 BV0
Bit
Number
Bit
Mnemonic
Function
7 BEN Baud-rate Generator Enable:
Setting this bit enables the baud-rate generator. Clearing this bit disables
the baud-rate generator, clears the baud-rate count value, and forces the
baud rate clock to zero.
6–0 BV6:0 Baud-rate Value:
The baud-rate value (BV) is the reload value for the baud-rate
generator’s seven-bit down counter. The baud-rate generator’s output is
a function of BV and the baud-rate generator’s input (BCLKIN), as
follows.
(Hz)
If you know the desired output baud-rate frequency, you can determine
BV as follows.
baud-rate output frequency (Hz)
BCLKIN
2BV 2+
----------------------=
BV
BCLKIN
2 baud-rate output frequency×
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