TDA7427 ST Microelectronics, TDA7427 Datasheet - Page 12

• Manufacturer Part Number: TDA7427
• Description: AM-FM RADIO FREQUENCY SYNTHESIZER AND IF COUNTER
• Manufacturer: ST Microelectronics

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.
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
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
CHIP ADDRESS
SUBADDRESS
T1, T2, T3 used for testing, in application mode they have to be ”0”
12/21
S
MSB
MSB
1
T3
1
MSB
1
1
T2
CHIP ADDRESS
0
0
0
T1
0
0
1
0
1
I
0 R/W
0
LSB
A3
ACK
0
0
0
0
0
0
0
0
1
1
1
1
1
T
MSB
0
A2
0
0
0
0
1
1
1
1
0
0
0
0
T
LSB
T
SUBADDRESS
0
A1
0
0
1
1
0
0
1
1
0
0
1
1
I
A3 A2 A1 A0
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”.
SOFTWARE SPECIFICATION
I
The interface protocol comprises:
LSB
2
A0
0
1
0
1
0
1
0
1
0
1
0
1
C Protocol
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)
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
LSB
ACK
MSB
DATA 1 to DATA n
FUNCTION
DATA
LSB
ACK
P