RS8953 Conexant Systems, Inc., RS8953 Datasheet - Page 83

• Manufacturer Part Number: RS8953
• Description: High-bit-rate Digital Subscriber Line (hdsl) Channel unit
• Manufacturer: Conexant Systems, Inc.

RS8953B/8953SPB
HDSL Channel Unit
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.
N8953BDSB
0x08—Transmit Payload Map (TMAP_1)
0x09—Transmit Payload Map (TMAP_2)
0x0A—Transmit Payload Map (TMAP_3)
0x0B—Transmit Payload Map (TMAP_4)
0x0C—Transmit Payload Map (TMAP_5)
7
7
7
7
7
BYTE12 TMAP[1:0]
BYTE16 TMAP[1:0]
BYTE20 TMAP[1:0]
BYTE4 TMAP[1:0]
BYTE8 TMAP[1:0]
6
6
6
6
6
5
5
5
5
5
BYTE11 TMAP[1:0]
BYTE15 TMAP[1:0]
BYTE19 TMAP[1:0]
BYTE3 TMAP[1:0]
BYTE7 TMAP[1:0]
4
4
4
4
4
Conexant
3
3
3
3
3
BYTE10 TMAP[1:0]
BYTE14 TMAP[1:0]
BYTE18 TMAP[1:0]
BYTE2 TMAP[1:0]
BYTE6 TMAP[1:0]
2
2
2
2
2
4.3 Transmit Payload Mapper
1
1
1
1
1
BYTE13 TMAP[1:0]
BYTE17 TMAP[1:0]
BYTE1 TMAP[1:0]
BYTE5 TMAP[1:0]
BYTE9 TMAP[1:0]
4.0 Registers
0
0
0
0
0
4-15