RS8953 Conexant Systems, Inc., RS8953 Datasheet - Page 45

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

RS8953B/8953SPB
HDSL Channel Unit
Figure 3-12. PRBS/BER Measurements
N8953BDSB
ROUTE_TBL
3.2.2.3 BER Meter
PRBS
Test Selected HDSL Payload
BER_SEL = NORMAL
HDSL
COMBINE_TBL
BER
PCM timeslots from TSER or RSER can be examined for test patterns on a per
timeslot-basis, or the entire framed or unframed PCM channel from TSER can be
examined (see PRBS_MODE in CMD_3; addr 0xE7 and BER_SEL in CMD_6;
addr 0xF3). When a test pattern is examined on a per timeslot-basis from receive
combination or transmit routing table assignments, the BER meter is only clocked
during enabled timeslots and expects a single test pattern to arrive in one
sequence from all enabled timeslots. The expected test pattern is selected from
one of four Pseudo-Random Bit Sequence (PRBS) patterns or a programmable
8-bit fixed pattern [FILL_PATT; addr 0xEA]. PRBS pattern selections are: 2
2
2
addr 0xE7] to determine the test measurement interval from a range of 2
lengths, starts BER measurement by issuing BER_RST [addr 0xEF], then
monitors test results [BER_METER; addr 0x1D] and test status [BER_STATUS;
addr 0x1E].
15
20
–1, 2
–1 PRBS with 14-zero limit. The MPU configures BER_SCALE [CMD_3;
23
–1 and Quasi-Random Signal Sequence (QRSS), where QRSS equals
RSER
TSER
BER_SEL = PCM SERIAL
Test Entire PCM Channel
Conexant
PRBS
BER
TSER
Test Selected PCM Timeslots
BER_SEL = PCM FRAMED
HDSL
PCM
3.0 Circuit Descriptions
ROUTE_TBL
3.2 PCM Channel
PRBS
BER
21
–2
31
4
3-13
–1,
bit