cx28560 Mindspeed Technologies, cx28560 Datasheet - Page 159

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

7.1
7.1.1
28560-DSH-001-B
Protocol-Independent Operations
Transmit
7.0 Basic Operations
The two main channel protocols, HDLC and transparent mode, are described in
subsequent sections of this chapter. HDLC and transparent mode operations perform
protocol-specific processing of their respective input and output serial bit streams,
and behave differently in their treatment of those bit streams during abnormal
conditions.
From a functional viewpoint, many of the CX28560 operations are protocol-
independent, though some behavior may differ between the transmitter and receiver.
The protocol-independent operations described below apply to all event and error
handling:
The CX28560 initiates data transfer to the serial interface only if the following
conditions are true:
If TxENBL bit is set to 0 (transmit port disabled), the serial data output signal is
placed in high-impedance three-state. If TxENBL = 1 (port enabled) and a time slot is
disabled, the corresponding time slot’s transmitter output is either a three-state or all
1s signal depending on the state of the TRITx bit field in the port’s TSIU Port
Configuration register (see
• During buffer controller, SLP channel protocol, and SIU serial port operations,
• If the CX28560 suspends a channel’s operation or deactivates a channel, the
• TxENBL bit set to 1 in
• Transmit channel is mapped to time slot(s), which are enabled in the port’s
• Transmit channel has been activated by a host service request.
• The channel number appears at least once in the active Flexiframe.
an event or error may occur that indicates the status of the message transfer
process or that affects the outcome of the overall message transfer process.
Unless masked, all such events and errors cause the CX28560 to write an
interrupt descriptor to the shared memory interrupt queue. Interrupt
descriptors identify the error or event condition, the transmit or receive
direction, and the affected channel or port number.
host must perform a channel reactivation by issuing a channel activation
service request. This is referred to as “requiring reactivation.”
Chapter
Mindspeed Technologies™
5.0, TSIU Time Slot Configuration register.
Advance Information
Chapter
Chapter
5.0).
5.0, TSIU Port Configuration register.
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