STV8203 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'STV8203' PDF : 31 Pages View PDF
STV8203
PROGRAMMING THE DEVICE (continued)
FIFQ2 - FIFQ1 (DCO Fine Frequency)
Address
Type
Reset
: 2C-3A
: R/W
: 1100 0100 for FIFQ2 - 1100 0111 for FIFQ1
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
CHANNEL 2 or CHANNEL 1 DCO FINE FREQUENCY (8LSB’s)
bit 0
The DCO’s, which are set to the carrier frequencyto be demodulated,are adjusted in two parts as follows :
C=
Fc
Fs
⋅
48,
where Fc is the carrier frequency, Fs is the crystal frequency
Take the nearest integer, Ci, for the 6 bits of the COFQ register
F
=
(C
−
Ci)
⋅
29
3
Take the nearest integer, Fi, for the 8 bits of the FIFQ register.
Common frequencies with Fs = 27MHz :
Fc (MHz)
5.5
5.74
5.85
6.0
6.552
Ci
decimal
binary
10
001010
10
001010
10
001010
11
001011
12
001100
decimal
-38
35
68
-57
-60
Fi
binary
11011010
00100011
01000100
11000111
11000100
ACOEFF2 - ACOEFF1 (PLL Loop Filter Proportional Coefficient)
Address
Type
Reset
: 2D-3B
: R/W
: 10010000 for ACOEFF2 - 0010 0011 for ACOEFF1
bit 7
DMD SW2 or 1
bit 6
0
bit 5
bit 4
COARSE A2 or A1
bit 3
SIGN A2 or A1
bit 2
bit 1
bit 0
FINE A2 or A1
DMD SW
: Mode switch : 0 = FM, 1 = QPSK
COARSE A, : Program the PLL (FM/QPSK carrier recovery) loop filter proportional coefficient A :
SIGNA, FINE A A coefficient = coarse + (sign x fine)
COARSE
Value
00
0
01
1
10
1/2
11
1/4
SIGN
0
+
1
-
FINE
000
001
010
011
100
101
110
111
Value
0
1/2
1/4
1/8
1/16
1/32
1/64
Not used
26/31
Share Link: 
