TSS463C ATMEL Corporation, TSS463C Datasheet - Page 24

• Manufacturer Part Number: TSS463C
• Description: Van Data Link Controller With Serial Interface
• Manufacturer: ATMEL Corporation

Generation of Internal
Signals
RI Signal (Return to Idle)
SDC Signal (Synchronous
Diagnosis Clock)
Progress)
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TIP Signal (Transmission in
TSS463C
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This signal is used to return to nominal mode in the three specified selection modes (see
“Diagnosis States” on page 22 and “Programming Modes” on page 25). The RI signal is
disabled in automatic selection mode.
The RI signal is a pulse generated when an EOF is detected. Thus, at the end of each
frame, regarding the diagnosis status bit Sa, Sb and Sc, the user can make its own
choice.
This time base is used by diagnosis system in automatic selection mode (see
Section “Programming Modes”, page 25) when no event is recorded on the bus.
The SDC is generated either by a special SDC divider connected to the timeslot clock,
or can be performed manually. The SDC clock period must be long compared to the
timeslot duration.
A typical SDC period should be greater than the maximum frame length appearing on
the VAN network.
This signal must be enabled to allow the transmission diagnosis (see Section “Transition
Analyses”, page 23).
The TIP turns on synchronously with the beginning of the transmission:
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The TIP turns off synchronously with the end of the transmission:
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This signal is not generated when the transmission logic only sends an ACK.
Transmission diagnosis
The transmission compares RxD1 and RxD2 inputs (through the input comparators
and the filters) with the data transmitted on TxD output.
At a time when the transmission logic generates a dominant - recessive transition,
the inputs can give different values. Taking into account the filtering delay, the bus
line seen as dominant is assumed to be correct, the other one, recessive, is
considered faulty. The diagnosis mode is changed to reflect that.
Protocol fault
The protocol fault is detected by counting the number of consecutive dominant
timeslots.
If eight consecutive timeslots are dominant, the diagnosis mode will change to the
major error mode.
for asynchronous bus access, the beginning of SOF;
for synchronous bus access, the beginning of the identifier field; and
for a request of in frame reply, the RTR bit of the command field.
after EOF;
after a losing of arbitration or a code violation detection; and
for a requestor of in frame reply, when the arbitration is lost on RTR the bit.
7601B–AUTO–02/06