TDA7333 Datasheet, PDF (11/21 Pages) STMicroelectronics – RDS/RBDS PROCESSOR

TDA7333
7.7 Programming through Serial bus interface
The serial bus interface is used to access the different registers of the chip. It is able to handle both I2C and SPI
transfer protocols, the selection between the two modes is done thanks to the pin CSN :
– if the pin CSN is high, the interface operates as an I2C bus.
– if the pin CSN is asserted low, the interface operates as a SPI bus.
In both modes, the device is a slave, i.e the clock pin SCL_CLK is only an input for the chip.
Depending on the transfer mode, external pins have alternate functions as following:
Table 7.
pin
SCL_CLK
SDA_DATAIN
SA_DATAOUT
function in
SPI mode (CSN=0)
CLK (serial clock)
DATAIN (data input)
DATAOUT (data output)
function in
I2C mode (CSN=1)
SCL (serial clock)
SDA (data line)
SA (slave address)
Eight registers are available with read or read/write access rights as following :
Table 8.
register
rds_int[7:0]
rds_qu[7:0]
rds_corrp[7:0]
rds_bd_h[7:0]
rds_bd_l[7:0]
rds_bd_ctrl[7:0]
sinc4reg[7:0]
testreg[7:0]
access rights
read/write
read
read
read
read
read/write
read/write
read/write
The meaning of each bit is described below :
function
interrupt source setting,synch., bne information
quality counter, actual block name
error correction status, buffer ovf information
high byte of current RDS block
low byte of current RDS block
frequency, quality sensitivity, plls setting
sinc4 filter settings (for internal use only)
test modes (for internal use only)
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