TDA7705_10 Datasheet, PDF (15/42 Pages) STMicroelectronics – Highly integrated tuner for AM/FM car radio

TDA7705
Figure 5. SPI modes
Function description
In the case of the TDA7705, the data are latched on the clock's rising edge, with CPOL = 1
and CPHA = 1 (mode 3 in the figure above). According to the specification of this mode, the
polarity of the CLK line when no communication is taking place is high.
A "write" communication example is shown in the figure below, for an unspecified number of
bits (see the relevant technical documentation for frame structure description):
Figure 6. SPI "write" sequence
CS
CLK
MOSI
MSB
...
...
...
...
...
...
...
...
...
...
LSB
The start condition is signaled by the CS line going low, and the stop condition by the CS
line going high. It is not allowed to toggle the CS line while the communication is going on.
A "read" communication example is shown in the figure below, for an unspecified number of
bits (see the relevant technical documentation for frame structure description ):
Figure 7. SPI "read" sequence
CS
CLK
MOSI
MSB
...
...
...
...
LSB
MISO
MSB
...
...
...
...
LSB
The red line is controlled by the TDA7705, whereas the black lines are controlled by the µP.
Doc ID 15938 Rev 8
15/42