TDA8822T PHILIPS [NXP Semiconductors], TDA8822T Datasheet - Page 12

• Manufacturer Part Number: TDA8822T
• Description: Universal I2C-bus programmable RF modulator
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
Example of programming
We want to program the TDA8822 in a UHF application, on channel 21 (picture carrier at 471.25 MHz) in a B/G standard
(sound carrier at 5.5 MHz from the picture carrier) with a Picture-to-Sound ratio of 12 dB, a modulation depth of 82.5%
and a deviation set to 50.5% in normal mode, without TPSG, output port on.
These are the values of the bits that must be programmed:
The protocol to the TDA8822 is illustrated in Table 10.
Table 10 Example of programming for the TDA8822.
1997 Jan 08
Address byte CA
F1: frequency
byte 1
F0: frequency
byte 0
C1: control byte 1
C0: Control byte 0
The video dividing ratio will be
TPSG bit will be set to logic 0
DEV2 will be set to logic 0, DEV1 to logic 1 and DEV0 to logic 0
PS2 will be set to logic 0, PS1 to logic 0 and PS0 to logic 1
MD2 will be set to logic 1, MD1 to logic 0 and MD0 to logic 0
SC1 will be set to logic 0 and SC0 to logic 1
P0 will be set to logic 1
RF0 will be set to logic 1
T0 will be set to logic 0.
Universal I
modulator
BYTE
2
C-bus programmable RF
BIT 7
MSB
1
0
0
1
1
BIT 6
N
1
0
1
0
0
=
---------------- -
f
ref
f
osc
BIT 5
8
0
0
1
1
0
=
471 250 000
------------------------------
7 812.5 8
BIT 4
0
1
1
0
0
12
BIT 3
=
1
1
0
0
1
7540
BIT 2
=
0
1
1
0
1
01110101110100
BIT 1
1
0
0
1
1
BIT 0
LSB
0
1
0
0
0
Preliminary specification
ACKNOWLEDGE
TDA8822
ACK
ACK
ACK
ACK
ACK