RELEASED
PM73123 AAL1GATOR-8
DATASHEET
PMC-2000097
ISSUE 2
8 LINK CES/DBCES AAL1 SAR
8. The RFIFO block buffers cells received from the UTOPIA Interface block.
9. The RALP performs pointer searches, checks for overrun and underrun
conditions, detects SN mismatches, checks for OAM cells, and extracts the
line data from the cells, and places the data into the receive buffer.
10.The RFTC plays the receiver buffer data onto the lines.
Four types of data are supported by the A1SP.
1. UDF-ML (Unstructured Data Format- Multi-Line). Unstructured bit stream for
line speeds < 15 Mbps. (supports 8 lines per A1SP) if all are under 2.5 Mbps).
2. UDF-HS (Unstructured Data Format- High Speed). Unstructured bit stream
for line speeds under 45 Mbps. (Only one line supported per A1SP).
3. SDF-FR (Structured Data Format- Frame). Channelized data without CAS
signaling. (Frame based structure).
4. SDF-MF (Structured Data Format- Multi-Frame). Channelized data with CAS
signaling. (Multi-Frame based structure).
9.2.1 AAL1 SAR Transmit Side (TxA1SP)
9.2.1.1 Transmit Frame Transfer Controller (TFTC)
The TFTC accepts deframed data from Line Interface Block. For structured data,
the TFTC uses the synchronization supplied by the Line Interface Block to
perform a serial-to-parallel conversion on the incoming data and then places this
data into a multiframe buffer in the order in which it arrives.
The TFTC monitors the frame sync signals and will realign when an edge is seen
on these signals that does not correspond to where it expects it to occur. It is not
necessary to provide an edge at the beginning of every frame or multiframe. The
AAL1gator-8 reads signaling during the last frame of every multiframe. For T1
mode, the AAL1gator-8 reads signaling on the 24th frame of the multiframe. For
E1 mode, the AAL1gator-8 reads signaling on the 16th frame of the multiframe.
A special case of E1 mode exists that permits the use of T1 signaling with E1
framing. Normally an E1 multiframe consists of 16 frames of 32 timeslots, where
signaling changes on multiframe boundaries. When E1_WITH_T1_SIG is set in
LIN_STR_MODE and the line is in E1 mode, the TFTC will use a multiframe
consisting of 24 frames of 32 timeslots. In this mode, the AAL1gator-8 reads
signaling on the 24th frame of the multiframe.
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