CN8478 Datasheet, PDF (178/221 Pages) Conexant Systems, Inc – Multichannel Synchronous Communications Controller (MUSYCC)

6.0 Basic Operation
6.4 Protocol Support
CN8478/CN8474A/CN8472A/CN8471A
Multichannel Synchronous Communications Controller (MUSYCC™)
6.4.9.1 Transmit Events
End of Buffer (EOB)
6.4.9.2 Receive Events
End of Buffer (EOB)
Frame Recovery (FREC)
If the host wants to send any more data on that channel, the host must
reactivate any transparent mode transmit channel that has issued an ONR error.
Notice there is no mechanism for transparent mode channels to ever enter the
IDLE transmission state.
Transmit events are informational and require no recovery actions.
Reason:
• DMAC reached the end of a buffer by servicing a number of octets equal
to the BLEN bit field in a Transmit Buffer Descriptor. For the transparent
mode, EOM is not a valid event because there is no concept of messages.
Effects:
• MUSYCC writes the Interrupt Descriptor in Interrupt Queue with
EVENT = EOB, DIR = 1 (per EOBI in Transmit Buffer Descriptor).
• MUSYCC continues with normal transparent mode processing by
processing to the next message structure.
• MUSYCC requires more data buffers.
Receive events are informational and require no recovery actions.
Reason:
• BLP reached the end of a buffer by transferring into shared memory a
number of octets equal to the BLEN bit field in a Receive Buffer
Descriptor.
Effects:
• MUSYCC writes the Interrupt Descriptor in Interrupt Queue with
EVENT = EOB, DIR = 0 (per EOBI in Receive Buffer Descriptor).
Reason:
• BLP detects that the serial interface transitions from an out-of-frame to an
in-frame condition.
Effects:
• The Interrupt Descriptor in Interrupt Queue with EVENT = FREC,
DIR = 0 (per MSKOOF in Group Configuration Descriptor).
• MUSYCC continues with normal transparent mode processing by
processing to the next message structure.
6-44
Conexant
100660E