Philips Semiconductors
Preliminary specification
I2C-bus controlled BTSC stereo/SAP decoder
TDA9850
I2C-BUS PROTOCOL
I2C-bus format to read (slave transmits data)
S
SLAVE ADDRESS
R/W
A
DATA
MA
DATA
P
Table 1 Explanation of I2C-bus format to read (slave transmits data)
NAME
DESCRIPTION
S
START condition; generated by the master
1011011 pin MAD not connected
Standard SLAVE ADDRESS (MAD)
Pin programmable SLAVE ADDRESS
1011010 pin MAD connected to ground
1 (read); generated by the master
R/W
A
acknowledge; generated by the slave
slave transmits an 8-bit data word
DATA
MA
P
acknowledge; generated by the master
STOP condition; generated by the master
Table 2 Definition of the transmitted bytes after read condition
MSB
LSB
D0
FUNCTION
BYTE
D7
D6
D5
D4
D3
D2
D1
Alignment read 1
Alignment read 2
ALR1
ALR2
Y
Y
SAPP
SAPP
STP
STP
A14
A24
A13
A23
A12
A22
A11
A21
A10
A20
Table 3 Function of the bits in Table 2
BITS
FUNCTION
STP
stereo pilot identification (stereo received = 1)
SAP pilot identification (SAP received = 1)
stereo alignment read data
for wideband expander
SAPP
A1X to A2X
A1X
A2X
for spectral expander
Y
indefinite
The master generates an acknowledge when it has received the first data word, ALR1, then the slave transmits the next
data word ALR2. The master next generates an acknowledge, then slave begins transmitting the first data word ALR1,
and so on until the master generates no acknowledge and transmits a STOP condition.
1995 Jun 19
15
NXP [ NXP ]
