STV8247 Datasheet, PDF (60/149 Pages) STMicroelectronics – Digital Audio Decoder/Processor for A2 and NICAM Television/Video Recorders

Register List
STV82x7
Bit Name
Bit [7:5]
QPSK_LK
FM2_CAR
FM2_SQ
FM1_CAR
FM1_SQ
Reset
Function
000 Reserved.
0 QPSK Lock Detection Flag
0: Not detected
1: Detected
0 Channel 2 FM/AM Carrier Detection Flag
0: Not detected
1: Detected
0 Channel 2 FM Squelch Detection Flag
0: Not detected
1: Detected
0 Channel 1 FM/AM Carrier Detection Flag
0: Not detected
1: Detected
0 Channel 1 FM Squelch Detection Flag
0: Not detected
1: Detected
Note: These registers allow direct access to the demodulator signal detectors.
AGC_CTRL
IF AGC Control Register
Address: 0Eh
Type: R/W
Bit 7
AGC_CMD
Bit 6
0
Bit 5
0
Bit 4
Bit 3
AGC_REF[2:0]
Bit 2
Bit 1
Bit 0
AGC_CST[1:0]
Bit Name
AGC_CMD
Bits[6:5]
AGC_REF[2:0]
Reset
Function
0 Automatic Gain Control Command Mode
Normally set to 0 enabling automatic mode. For L/L’ standards, the AGC should be switched off
due to the presence of the AM sound carrier. In this case, a fixed gain value should be set using
the AGCS register.
0: Automatic mode. AGC controlled by the Autostandard function. (Default)
1: Manual/Forced mode
00 Reserved.
100 This bitfield is used to defines the clipping level which adjusts the allowable proportion of samples
at the input of the ADC which will be clipped. The AGC tries to maximize the use of the full scale
range of the ADC. The default setting gives a ratio of 1/256.
Clipping Ratio
Clipping Ratio
000:
1/16 (Single carrier)
001:
1/32
010:
1/64
011:
1/128
100:
1/256 (Default)
101:
1/512
110:
1/1024
111:
1/2048 (Multiple carriers)
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