cx28560 Mindspeed Technologies, cx28560 Datasheet - Page 79

• Manufacturer Part Number: cx28560
• Description: Hdlc Controller
• Manufacturer: Mindspeed Technologies

CX28560 Data Sheet
4.4
28560-DSH-001-B
Buffer Controller
The buffer controllers (RxBUFFC and TxBUFFC) manage all memory
operations between the SLPs and the host interface. The BUFFC receives
requests from the SLPs either to fill or to flush internal FIFO buffers, provides/
receives data for the SLPs, controls the Flexiframe timing scheduler, and transfers
data to/from the POS-PHY data interface (through the host interface). In addition,
the TxBUFFC communicates with the system across the POS-PHY
FlowConductor Interface by sending report packets containing information
regarding the amount of space freed in channels’ buffers.
The BUFFC main features are as follows:
• Handles up to 2047 logical channels
• Static internal buffer allocation
• User has full control of internal buffer characteristics:
• Message/Fragment handling
• Automatic Tx Abort Command generation from TERR pin
• Flexiframe characteristics:
• Receive Performance Monitoring counters:
• Transmit Performance Monitoring counters:
• Receive Interrupts
• Transmit Interrupts
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Mindspeed Technologies™
standard buffer length can be increased to support longer fragments
user-programmable thresholds in the transmit direction
FIFO flushing capability (after soft chip reset, channel activation, and
channel deactivation service request)
Addition/interpretation of message and fragment headers
Time division scheduling scheme
Maximum 21,504 K slots per frame
Enables dynamic channels reconfiguration
Configurable gap between services
In the Transmit direction, controls FlowConductor requests
Octets
Packets
Packets with alignment errors
Packets with too short errors
Packets with too long errors
Packets with FCS errors
Packets terminating in an abort
Octets
Packets
Packets transmitted terminating in an abort signal
Rx EOM—End Of Message without an error
Rx EOM—End Of Message with error (Overflow, OOF, COFA, FCS,
ALIGN, ABT, LNG)
SHT—Too short. Also used as a general errored message interrupt
when data has not yet been passed on for a message. (e.g., a 9-bit
message)
TxBOVFLW—BUFFC channel buffer overflow
TxPOSERR—An error occurred on the POS-PHY FlowConductor
POS-PHY buffer overflow, Data POS-PHY parity error, Data POS-
PHY TxERR pin asserted, or Data POS-PHY internal buffer
overflow.
Advance Information
CX28560 Serial Interface
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