STV8203 ST Microelectronics, STV8203 Datasheet - Page 23

• Manufacturer Part Number: STV8203
• Description: MULTISTANDARD TV SOUND DEMODULATOR
• Manufacturer: ST Microelectronics

PROGRAMMING THE DEVICE (continued)
IAGCS (Internal AGC Control Value)
Address
Type
Indicates the value of the internal AGC control signal.
Normally, the mean value should equal the value set in the IAGCR register when a signal is being
demodulated.
FFFIXL (Clock Generator Fine frequency)
Address
Type
Reset
See FCFIX register for explanation.
FFFIXH (Clock Generator and Fine Frequency Control)
Address
Type
Reset
DEMOD MODE M2:M0
CLOCK GEN FINE FREQ : Clock generator fine frequency (4 MSB’s) ( see FCFIX for explanation).
FCFIX (Clock Generator Coarse Frequency)
Address
Type
Reset
The bits [5:0] together with FFFIXH bits [3:0] and FFFIXL bits [7:0] can be used to programme the internal
clock generator for different quartz crystal frequencies ; the default value is for 27MHz.
P 182
FCFIX = INT(P)
FFFIX = 256 x (16 x REM(P) - 1)
Note that 0
Example : Fref = 27MHz, FCFIX = 17, FFFIX = 3584.
bit 7
bit 7
bit 7
bit 7
0
0
Fqpsk
Fref
FFFIX <3840 so there is a small range of frequencies which cannot be used.
: 16
: R
: 17
: R/W
: 0000 0000
: 18
: R/W
: 0110 1110
: 19
: R/W
: 0001 0001
bit 6
bit 6
bit 6
bit 6
193 with Fref = crystal frequency, Fqpsk = 32 x 728kHz = 23.296MHz.
0
DEMOD MODE M2:M0
: Controls the demodulator mode (only when register Ehex bits[3:0] = 0000) :
CLOCK GENERATOR FINE FREQUENCY (8 LSB’s)
The FM discriminator modulation full range can be set at :
- narrow mode : 250kHz ( 125kHz),
- wide mode : 500kHz ( 250kHz).
bit 5
bit 5
bit 5
bit 5
MODE[6:4]
(INT: integer part)
(REM: fractional remainder)
X00
X01
010
011
110
111
bit 4
bit 4
bit 4
bit 4
CLOCK GENERATOR COARSE FREQUENCY
IAGC-CTRL
bit 3
bit 3
bit 3
bit 3
CH1 FM
Normal
Normal
Normal
Wide
Wide
Wide
CLOCK GEN FINE FREQ (4 MSB’s)
bit 2
bit 2
bit 2
bit 2
QPSK System B/G/L
QPSK System B/G/L
bit 1
bit 1
bit 1
bit 1
CH2 FM/QPSK
QPSK System I
QPSK System I
FM Normal
FM Wide
STV8203
bit 0
bit 0
bit 0
bit 0
23/31