Information

 2010 Microchip Technology Inc. DS80243M-page 5
PIC16F631/677/685/687/689/690
1.5 Auto-baud sequence cannot be aborted in
some cases.
If an auto-baud is started but no edges are
received, there is no way to leave Auto-Baud
mode.
Work around
Use the Watchdog Timer to reset the entire
device.
Fix
Rev. A5 Silicon and later revisions.
Affected Silicon Revisions
PIC16F687/PIC16F689/PIC16F690
1.6 Clearing SPEN does not reset EUSART state
machine correctly.
When SPEN is cleared, the entire EUSART is
frozen. When SPEN is set, the EUSART resumes
where it left off. This can cause some unexpected
behavior.
Work around
To reset the EUSART, toggle TXEN and CREN
after clearing SPEN. This will reset the transmit
and receive state machines.
Fix
Rev. A5 Silicon and later revisions.
Affected Silicon Revisions
PIC16F687/PIC16F689/PIC16F690
1.7 Extra character transmitted after auto-baud.
If TXEN is high when ABDEN is set, it will be
cleared as soon as the auto-baud process
begins, and reset as soon as the auto-baud
process completes. When TXEN is reset, the
character in the transmit queue will be
transmitted.
Work around
Before starting auto-baud, clear TXEN. This will
reset the transmit state machine correctly. After
the auto-baud is complete and the firmware has
brought TXEN high, no character will be
transmitted.
Fix
Rev. A5 Silicon and later revisions.
Affected Silicon Revisions
PIC16F687/PIC16F689/PIC16F690
A3 A4 A5 A6
XX
A3 A4 A5 A6
XX
A3 A4 A5 A6
XX