IA82510

Data Sheet

Asynchronous Serial Controller

February 25, 2011

IA211001219-05

http://www.Innovasic.com

UNCONTROLLED WHEN PRINTED OR COPIED

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Page 23 of 25

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Errata No. 14

Problem:

Unreliable transmits in AUTO TX mode.

Description:

Many systems use the RTS output to activate the line transceiver. When the

Transmit Mode field in the TMD register is set to semi-auto or automatic mode, RTS is controlled

by the TX state machine. On the first character, RTS asserts at the same time as the start bit on

the TXD output, whereas the original Intel device asserts RTS a full bit time before assertion of

the start bit on TXD. At full temperature range, the width of the start bit can be altered to the

point of confusing the downstream receiver.

Workaround:

Change firmware to Manual TX mode to control RTS vs. start of character.