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XC161 Derivatives
Peripheral Units (Vol. 2 of 2)
Serial Data Link Module SDLM
User’s Manual
22-8
V2.2, 2004-01
SDLM_X, V2.0
22.2.2.1
4x Mode
•
If high speed mode is used, all J1850 nodes should be configured to 4x mode when
supported.
•
Those nodes which do not support 4x mode need to tolerate high speed operation
(no error sign).
•
Enable bit EN4X.
•
A Break symbol occurrence will generate an interrupt.
•
After Break occurrence CPU needs to reset RX/TX status flags.
•
The transceiver delay should not exceed 4
µ
s.
22.2.2.2
Break Operation
•
Break allows bus communication to be terminated.
•
All nodes are reset to a ‘reset-to-receive’ state (reset status bits by CPU).
•
After Break symbol transition an IFS has to follow for re-synchronization purpose.
•
If a break is sent, the current frame is ignored (if any).
•
A break transmission can be generated setting bit SBRK.
•
A break reception is indicated by bit BRK being set.
Note: After a hardware reset operation the SDLM module is disabled.