4.0 Registers
4.7 HDSL Channel Configuration
RS8953B/8953SPB
HDSL Channel Unit
0xF5—HDSL Frame Length (HFRAME_LEN_HI)
7
—
6
—
5
—
4
—
3
—
2
—
1
—
0
HFRAME_LEN[8]
HFRAME_LEN[8:0]
HDSL Payload Block Length—Contains the number of BCLKn bits, in the range of 16 to 512,
that are transmitted and received in an HDSL payload block. Each payload block is comprised
of an integer number of 8-bit bytes plus an additional F-bit or Z-bit. The RS8953B repeats the
payload block length 48 times to form one HDSL frame. A value of 15 selects a 16-bit payload
block length; therefore, the programmed value of HFRAME_LEN equals eight times the
number of payload bytes. For example, a value of 96 (0x60) selects a 12-byte T1 payload or
144 (0x90) selects an 18-byte E1 payload. Value written to HFRAME_LEN are copied into
HFRAME2_LEN and HFRAME3_LEN.
In theory, the HDSL frame length can be different for each loop. But if the HDSL frame
lengths are not close to the same value, RFIFO errors will probably occur. For this reason, we
do not recommend different values for the HDSL frame length.
0xF8—HDSL Frame Length (HFRAME2_LEN_LO)
7
6
5
4
3
2
1
0
HFRAME_LEN[7:0]
0xF9—HDSL Frame Length (HFRAME2_LEN_HI)
7
—
6
—
5
—
4
—
3
—
2
—
1
—
0
HFRAME_LEN[8]
HFRAME2_LEN[8:0]
HDSL Payload Block Length—Contains the number of BCLK2 bits in the range of 16 to 512,
that are transmitted and received in an HDSL payload block for Channel 2.
In theory, the HDSL frame length can be different for each loop. But if the HDSL frame
lengths are not close to the same value, RFIFO errors will probably occur. For this reason, we
do not recommend different values for the HDSL frame length.
0xFA—HDSL Frame Length (HFRAME3_LEN_LO)
7
6
5
4
3
2
1
0
HFRAME_LEN[7:0]
4-30
Conexant
N8953BDSB
CONEXANT [ CONEXANT SYSTEMS, INC ]
