MT312 Zarlink Semiconductor, MT312 Datasheet - Page 53

• Manufacturer Part Number: MT312
• Description: Satellite Channel Decoder
• Manufacturer: Zarlink Semiconductor

8.2.5
This is effectively the Viterbi Bit Error Rate.
RS_BERCNT[23:0]: These three registers provide a measurement of the number of bit errors corrected by the
Reed-Solomon decoder. Reading the high byte stops the count incrementing. Reading the low byte resets all three
bytes and restarts the count incrementing again.
Where:
e.g.
8.2.6
RS_UBC[15:0]: These two registers provide a measurement of the Reed-Solomon uncorrected block errors.
Reading the high byte resets the byte and stops the count incrementing. Reading the low byte resets the byte and
restarts the count incrementing again.
where:
Viterbi BER =
RS_BERCNT_M
RS_BERCNT_H
RS_BERCNT_L
RS_UBC_H
RS_UBC_L
NAME
NAME
Reed-Solomon bit errors corrected registers 14 - 16 (R)
Reed-Solomon uncorrected block errors registers 17 - 18 (R)
dt = delta time between two readings in sec (recommend 20s for 20 - 30 MS/s signals)
for Rs = 27.5MS/s, CR = 3/4 and dt = 20 sec
Rs = symbol rate in Baud
CR = Viterbi code rate
In denominator: the factor 2 is for QPSK, change it to 1 for BPSK
dt = delta time between two readings in sec
Rs = symbol rate in Baud
CR = Viterbi code rate
Blk_size = 1632 bits for DVB and 1096 bits for DSS
In denominator, the factor 2 is for QPSK, change it to 1 for BPSK
Viterbi BER
ADR
RS_BERCNT[23:0]
17
18
dt * Rs * 2 * CR
ADR
14
16
15
=
RS_UBC[15:8] - Reed-Solomon uncorrected block errors (high byte)
bit-7
RS_UBC[7:0] - Reed-Solomon uncorrected block errors (low byte)
--------------------------------------------------------------- -
20
RS_BERCNT[23:0]
RS_BERCNT[15:8] - Reed-Solomon bit errors corrected (middle byte) R 00
RS_BERCNT[23:16] - Reed-Solomon bit errors corrected (high byte)
bit-7
RS_BERCNT[7:0] - Reed-Solomon bit errors corrected (low byte)
27.5 10
bit-6
bit-6
Block error rate
6
bit-5
2 3
bit-5
4
Zarlink Semiconductor Inc.
=
RS_BERCNT[23:0]
-------------------------------------------------- -
bit-4
MT312
=
bit-4
8.25 10
RS_UBC[15:0] Blk_size
------------------------------------------------------------------- -
53
dt Rs 2 CR
bit-3
bit-3
8
bit-2
bit-2
bit-1
bit-1
bit-0
bit-0
R
R
Design Manual
R 00
R 00
hex
Def
00
00
hex
Def