MT312 Zarlink Semiconductor, MT312 Datasheet - Page 52

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

8.2.3
bit-15:
M_SNR[14:0]: These two registers provide a indication of the signal to noise ratio of the channel being received by
the MT312. It should not be taken as the absolute value of the SNR.
The equation given only holds for Es/N0 values in the range 3 to 15 dB, i.e. Eb/N0 values in the range 0 to 12 dB.
8.2.4
This is effectively the QPSK Bit Error Rate.
VIT_ERRCNT[23:0]: This is the count of bits corrected by the Viterbi decoder. This value is updated when the
Viterbi error timer (VIT_ERRPER) expires (indicated by bit-2 in register FEC_INT) and is NOT reset by reading.
QPSK_BER =
VIT_ERRCNT_M
VIT_ERRCNT_H
VIT_ERRCNT_L
M_SNR_H
M_SNR_L
Eb/N0 ~
NAME
NAME
Measured Signal-to-Noise-Ratio registers 9 - 10 (R)
Viterbi error count at Viterbi input registers 11 - 13 (R)
Reserved
VIT_ERRPER[23:0] * 4
13312 - M_SNR[14:0]
VIT_ERRCNT[23:0]
ADR
ADR bit-7 bit-6 bit-5 bit-4 bit-3 bit-2 bit-1 bit-0
09
10
11
12
13
683
VIT_ERRCNT[15:8] - Viterbi error count (middle byte) R
VIT_ERRCNT[23:16] - Viterbi error count (high byte)
Reserved
VIT_ERRCNT[7:0] - Viterbi error count (low byte)
bit-7
dB
bit-6
M_SNR[7:0] measured SNR (low byte)
Zarlink Semiconductor Inc.
M_SNR[14:8] measured SNR (high byte)
bit-5
MT312
52
bit-4
bit-3
bit-2
R
R
bit-1
hex
Def
00
00
00
bit-0
Design Manual
R
R
hex
Def
00
00