BT8954 CONEXANT [Conexant Systems, Inc], BT8954 Datasheet - Page 64

• Manufacturer Part Number: BT8954
• Description: VOICE PAIR GAIN FRAMER
• Manufacturer: CONEXANT [Conexant Systems, Inc]

4.0 Registers
4.6 DSL Channel Configuration
4.6 DSL Channel Configuration
The DSL Channel Configuration Write registers are listed in
Table 4-4. DSL Channel Configuration Write Register
DFRAME_LEN[7:0]
SYNC_WORD[6:0]
4-12
0xA0—DSL Frame Length (DFRAME_LEN)
0xA1—Sync Word (SYNC_WORD)
Address
0xA0
0xA1
0xA2
0xA3
—
7
7
Register Label
RFIFO_WL_LO
DFRAME_LEN
RFIFO_WL_HI
SYNC_WORD
DSL Frame Length—Contains the number of BCLK bits (less 1), in the range of 8 to 152, that
are transmitted and received in a DSL payload block. Each payload block consists of an integer
number of 8-bit bytes (1 byte per voice channel) plus a variable number of S-bits (0–8) plus 0
or 1 EXTRA_Z_BIT. Therefore, DFRAME_LEN = #Voice Channels x 8 + #S-bits, –1 if
EXTRA_Z_BIT (CMD_1; addr 0xC0) = 0 but DFRAME_LEN = Voice Channels x 8 + SBITS
if EXTRA_Z_BIT = 1.
SYNC_WORD—Holds the 7 sign bits
word. Transmit SYNC word magnitude bits are forced to 0. SYNC_WORD[0] is the sign bit of
the first transmit quat. Sign precedes magnitude on the transmit data (TDAT) output. The
receive framer searches DSL data (RDAT) for patterns matching SYNC_WORD.
6
6
5
5
0 = Negative sign bit
1 = Positive sign bit
Bits
8
7
8
1
4
4
DFRAME_LEN[7:0]
Conexant
SYNC_WORD[6:0]
of the 7-quat (14-bit) transmit and receive SYNC
Table
3
3
4-4.
SYNC Word (sign only)
RX FIFO Water Level
RX FIFO Water Level
Name/Description
DSL Frame Length
2
2
Voice Pair Gain Framer
1
1
N8954DSC
Bt8954
0
0