TDA7427 Datasheet, PDF (12/21 Pages) STMicroelectronics – AM-FM RADIO FREQUENCY SYNTHESIZER AND IF COUNTER

TDA7427
dress being transmitted.
After this comparison, the TDA7427 will generate
an ”acknowledge” on the SDA line and will per-
form either a read or write operation according to
the state of R/W bit.
following words transmitted to the TDA7427 will
be considered as Data. The internal address will
be automatically incremented. After each word re-
ceipt the TDA7427 will answer with an ”acknow-
ledge”.
Write Operation
Following a START condition the master sends a
slave address word with the R/W bit set to ”0”.
The TDA7427 will ”acknowledge” after this first
transmission and wait for a second word (the
word address field).
This 8 bit address field provides an access to any
of the 8 internal addresses. Upon receipt of the
word address the TDA7427 slave device will re-
spond with an ”acknowledge”. At this time, all the
SOFTWARE SPECIFICATION
I²C Protocol
The interface protocol comprises:
A start condition (s)
A chip address byte (the LSB determines
read/write transmission)
A sub-address byte.
A sequence of data (N-bytes + acknowledge)
A stop condition (P)
CHIP ADDRESS
SUBADDRESS
DATA 1 to DATA n
MSB
LSB MSB
LSB MSB
S 1 1 0 0 0 1 0 R/W ACK T T T I A3 A2 A1 A0 ACK
ACK = Acknowledge
S = Start
P = Stop
I = Auto Increment
T = used for testing (in application mode they have to be ” 0”)
MAX CLOCK SPEED 400kbits/s
DATA
LSB
ACK P
CHIP ADDRESS
MSB
LSB
1
1
0
0
0
1
0
0
SUBADDRESS
MSB
T3
T2
T1
I
A3
A2
A1
0
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
0
1
0
0
1
0
1
1
0
1
0
1
T1, T2, T3 used for testing, in application mode they have to be ”0”
LSB
A0
0
1
0
1
0
1
0
1
0
1
0
1
FUNCTION
Charge pump control
PLL counter 1 (LSB)
PLL counter 2 (MSB)
PLL reference counter 1 (LSB)
PLL reference counter 2 (MSB)
PLL lockdetector control and PLL mode select
IFC reference counter 1 (LSB)
IFC reference counter 2 (MSB) and IFC mode select
IF counter control 1
IF counter control 2
Oscillator adjust
Port extension
page mode off
page mode enabled
12/21