4.0 Registers
RS8953B/8953SPB
4.10 Data Path Options
HDSL Channel Unit
INSERT_EN
Enable INSERT—Controls the state of the internal MUX and the INSERT output pin during
the corresponding PCM timeslot’s sample time. The next table entry is programmed to select
the previous timeslot (ROUTE = 11) and to place INSDAT data from the previous timeslot into
the TFIFO.
0 = INSERT output pin remains inactive (low)
1 = INSERT output pin active (high)
0xEE—Receive Combination Table (COMBINE_TBL)
MPU access to the Receive Combination Table’s (COMBINE_TBL) single register is enabled by writing
COMB_EN [CMD_3; addr 0xE7], and by writing a maximum of 64 table entries sequentially to
COMBINE_TBL. Each write increments the table pointer, and the first write corresponds to the first receive
PCM timeslot. Subsequent writes increment the table pointer to successive timeslots. After writing the required
number of table entries (see ROUTE_TBL), the MPU writes COMB_EN to disable table access, and then writes
RFIFO_RST [addr 0x62] on every HDSL channel to realign the receive elastic stores. The MPU possibly writes
RX_RST [addr 0xF1] if the aggregate PCM data rate has been modified. Subsequent table changes can rewrite
entries only up to and including the last desired modification.
7
6
5
4
3
2
1
0
—
—
DBANK_SEL
DROP_EN
BER_EN
COMBINE[1:0]
COMBINE[1:0]
Combine Code—Selects one of four data sources for output on RSER during the respective
receive PCM timeslot destination. The data source is selected from one of three HDSL receive
channels or the DBANK register. The first combine code that selects data from a HDSL
channel will receive the first payload byte mapped from that channel’s payload block, as
determined by the payload map [RMAP; addr 0x64]. Whenever combine [1:0] is not 00,
DBANK_SEL[1:0] must be 00.
COMBINE[1:0]
Source of RSER Data
Determined by DBANK_SEL[1:0]
HDSL receive channel 1
00
01
10
11
HDSL receive channel 2
HDSL receive channel 3
BER_EN
BER Meter Enable—Places a copy of the respective PCM timeslot’s data into the BER meter.
Any number of timeslots may be copied without affecting throughput.
0 = BER Meter ignores PCM timeslot
1 = BER Meter receives copy of PCM timeslot data from RSER
DROP_EN
Enable DROP—Controls the state of the DROP output pin which marks the respective timeslot
coincident with data output on RSER.
0 = DROP output pin remains inactive (low)
1 = DROP output pin active (high)
4-42
Conexant
N8953BDSB
CONEXANT [ CONEXANT SYSTEMS, INC ]
