peb3456 Infineon Technologies Corporation, peb3456 Datasheet - Page 64

• Manufacturer Part Number: peb3456
• Description: Channelized T3 Termination With Ds3 Framer, M13 Multiplexer, T1/ E1 Framers And 256 Channel Hdlc/ppp Controller
• Manufacturer: Infineon Technologies Corporation

or PPP mode.
RAB
ILEN
CRC
4.3.3
The data management unit receive transfers data for each of the 256 logical receive
channels from the internal receive buffer to the data sections of the corresponding
channel. To fulfill the task it has to be initialized for operation, which is described in
When the TE3-CHATT completes a data section, which included the end of a frame
(C bit and FE bit are set), or when the TE3-CHATT branches to a new linked list due to
a 'Receive Abort/Branch' command the status information bits RAB, ILEN, CRC, RFOD
and MFL are updated as part of the receive status update. In the abort scenario, the C
bit will always be set. Bit FE will be set only, if the particular channel operates in HDLC
RFOD
MFL
“Channel Programming / Reprogramming Concept” on Page
the channel information for the data management unit is the address pointer to the first
receive descriptor, the channel interrupt queue and the channel interrupt mask.
The first receive descriptor of a channel is fetched from system memory and stored in
the chip internal channel database the first time the receive buffer requests a data
transfer for the channel. The descriptor contains a pointer to the data section, the size of
the provided data section and a pointer to the next receive descriptor.
The data transfer is requested as soon as a programmed receive buffer threshold is
reached. This threshold is programmed during channel setup on a per channel basis.
Task of the data management unit is to calculate the maximum number of bytes that can
Data Sheet
Data Management Unit Receive
Receive Abort
This bit is set when
•the incoming serial data stream contained an abort sequence, or
•an incoming frame was aborted by the command ’Receive Abort/
•when a channel is switched off while a frame is being received.
Illegal length
This bit is set, when the length of the incoming data packet was not a
multiple of eight bits.
CRC Error
This bit is set, when the checksum of an incoming data packet was
different to the internally calculated checksum.
Receive Frame Overflow
This bit is set, when a receive buffer overflow occurred during data
reception.
Maximum Frame Length
This bit is set, when the length of the incoming data packet exceeded the
value programmed in CONF1.MFL.
Branch’, or
64
Functional Description
163. Relevant part of
PEB 3456 E
05.2001