4 ssio baud-rate control register (ssiobaud), Figure 1318. ssio baud-rate control register (ssi – Intel 386 User Manual

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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

Ч

---------------------------------------------------------------------------------

1

=

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