RELEASED
PM73123 AAL1GATOR-8
DATASHEET
PMC-2000097
ISSUE 2
8 LINK CES/DBCES AAL1 SAR
Field (Bits)
Description
SEQ_NUM
(14:12)
The Sequence number of the next cell, used by
CSD. Initialize to “000”.
NULL_BITMASK_CELL Set to 1 by CSD to send null cell. Initialize to “0”.
(11)
SCH_BUT_DONT_SEN Used internally by CSD to spread NULL cells.
D_NULL
Initialize to 0.
(10)
Only used by CSD in DBCES mode. When
operating in DBCES mode this register must be
initialized to the structure size minus the portion of
a structure that fits in the first cell. The formula to
calculate this value is:
CSD_BYTES_LEFT (9:0)
struct_size - ((46-bitmask_size) MOD struct_size)
The number of data bytes in the first cell is 47
minus the structure pointer and the bitmask size.
The MOD operation determines the number of
bytes from the structure that make it into the first
cell. This number is then subtracted from the
structure size to determine how many bytes are left
in the structure after the first cell.
10.3.8 RESERVED (Transmit Data Buffer)
This structure is reserved and must be initialized to 0 at initial setup. Software
modifications to this location after setup will cause incorrect operation.
Organization: 4 Kbytes x 8 line– - Each line is allocated a separate 128 frame
buffer memory. For E1 applications, this is large enough to store eight
multiframes (32 DS0s x 16 frames x 8 multiframes = 4096 bytes). In T1 mode, 96
frames or four multiframes are stored (24 * 24 * 4 = 2304 bytes). T1 storage uses
32 bytes per frame and 32 frames per multiframe to simplify address generation.
Every data byte is stored in the multiframe line buffers in the order in which it
arrives.
If E1_with_T1_SIG is set, data is arranged as if in T1 mode.
Base address within A1SP: 4000h
Index(line): 800h
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