RELEASED
PM73123 AAL1GATOR-8
DATASHEET
PMC-2000097
ISSUE 2
8 LINK CES/DBCES AAL1 SAR
Field (Bits)
Description
FRAMES_PER_CELL
(13:8)
A 6-bit integer specifying the maximum number of
frames required to have enough data to construct a
cell (round up of BYTE_PER_CELL/number of
DS0s assigned) plus 1. For example, for a T1 line in
SDF-FR mode with five DS0s, initialize this field to
11. In T1 SDF-MF, T1 SDF-FR, and E1_w_T1_sig
modes, FRAMES_PER_CELL is encoded as the
number of 24-frame multiframes required in bit 13
and the number of frames mod 24 in bits 12:8. In
AAL0 mode this field is set to 48 (in T1 mode this is
encoded as 1 MF and 24 frames: 111000B). In all
other modes, including unstructured T1 mode,
encode this value as the maximum number of 256
bit increments required to create a cell. For
unstructured mode with full cells, set this value to 3.
• For T1 SDF-MF single DS0 queues,
encode the value 48 as one multiframe
and 24 frames: 0x38.
• When calculating the
FRAMES_PER_CELL value, do not
subtract the bytes used by signaling
nibbles from the value. For example, for
an SDF-MF, single DS0, full cell
connection, use the value 47 + 1 = 48
and not 46 + 1 = 47.
• For SDF-MF connections using partial
cells, set FRAMES_PER_CELL to (round
up of BYTE_PER_CELL/number of DS0s
assigned) plus 2. This prevents
scheduling more than one cell per frame.
• FRAMES_PER_CELL is ignored for lines
with the LOW_CDV bit set in the
LIN_STR_MODE location.
PMC-SIERRA, INC. PROPRIETARY AND CONFIDENTIAL
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