RS8953B/8953SPB
4.0 Registers
HDSL Channel Unit
4.3 Transmit Payload Mapper
4.3 Transmit Payload Mapper
The Transmit Payload Map (TMAP_1–TMAP_9) determines whether HDSL payload bytes (byte1 through
byte36) are supplied from PCM timeslots, DBANK registers, or the HDSL auxiliary channel data. All routed
timeslots to a given channel’s TFIFO must also be mapped out of the TFIFO. The RS8953B sequentially maps
payload and cannot rearrange byte ordering but allows payload from the DBANK registers to be interleaved
with PCM data. If PCM transmit data is input-aligned to MSYNC, then the first TMAP byte to select PCM
receives the first routed PCM timeslot from the transmit PCM multiframe (i.e., PCM frame 0 maps to HDSL
payload block 1). If PCM data is not aligned to MSYNC, then payload bytes mapped from the TFIFO are not
aligned to PCM timeslots and HDSL payload blocks are not aligned to PCM frames. In T1 mode, TMAP must
be programmed to supply F-bits, by enabling one extra byte of payload at the end of the payload block.
0x08—Transmit Payload Map (TMAP_1)
7
6
5
4
3
2
1
0
BYTE4 TMAP[1:0]
BYTE3 TMAP[1:0]
BYTE2 TMAP[1:0]
BYTE1 TMAP[1:0]
0x09—Transmit Payload Map (TMAP_2)
7
6
5
4
3
2
1
0
BYTE8 TMAP[1:0]
BYTE7 TMAP[1:0]
BYTE6 TMAP[1:0]
BYTE5 TMAP[1:0]
0x0A—Transmit Payload Map (TMAP_3)
7
6
5
4
3
2
1
0
BYTE12 TMAP[1:0]
BYTE11 TMAP[1:0]
BYTE10 TMAP[1:0]
BYTE9 TMAP[1:0]
0x0B—Transmit Payload Map (TMAP_4)
7
6
5
4
3
2
1
0
BYTE16 TMAP[1:0]
BYTE15 TMAP[1:0]
BYTE14 TMAP[1:0]
BYTE13 TMAP[1:0]
0x0C—Transmit Payload Map (TMAP_5)
7
6
5
4
3
2
1
0
BYTE20 TMAP[1:0]
BYTE19 TMAP[1:0]
BYTE18 TMAP[1:0]
BYTE17 TMAP[1:0]
N8953BDSB
Conexant
4-15
CONEXANT [ CONEXANT SYSTEMS, INC ]
