TDA7529 Datasheet, PDF (30/60 Pages) STMicroelectronics – RF front-end for AM/FM DSP car-radio with IF sampling

Tuning state machine
TDA7529
5.1.3
Mode 010: search
Figure 9. Search timing diagram
EVENTS
bus
STOP
event
regs
swap
TIME
transmission with subaddr. bit 7 = 1 wait T1ms
AFSAMPLE
wait for Tplllock
wait 50 us
5.1.4
AFHOLD
B.E. OPERATION
mute audio
quality dets in fast mode
AC00046
This mode is used to jump to a different frequency and stay there, with audio muted.
AFSAMPLE can be used to tell the back-end when to mute the audio output.
AFHOLD can be used to tell the back-end to switch to faster time constants for quick quality
acquisition.
Mode 011: AF update
Figure 10. AF update timing diagram
EVENTS
bus
STOP
event
regs
swap
regs
swap
TIME
transmission with subaddr. bit 7 = 1
AFSAMPLE
AFHOLD
B.E. OPERATION
mute audio
hold
freeze
AF qual
unmute audio
AC00047
This mode is used to jump to an AF frequency, check its quality, jump back to the starting
frequency and continue reception.
AFSAMPLE can be used to tell the back-end when to acquire the AF frequency quality.
AFHOLD can be used to tell the back-end to mute/unmute the audio and keep normal
processing on hold.
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