BCM4354 datasheet(47/165 Pages) CYPRESS

47 / 165 page

Document Number: 002-14809 Rev. *J

Page 47 of 165

CYW4354

■ High Cut: A programmable high-cut filter is provided to reduce the amount of high-frequency noise caused by static in the output

audio signal. Like the soft mute circuit, it is fully programmable to allow for any amount of high cut based on the FM signal C/N.

■ Audio Pause Detect: The FM receiver monitors the magnitude of the audio signal and notifies the host through an interrupt when

the magnitude of the signal has fallen below the threshold set for a programmable period. This feature can be used to provide

alternate frequency jumps during periods of silence to minimize disturbances to the listener. Filtering techniques are used within the

audio pause detection block to provide more robust presence-to-silence detection and silence-to-presence detection.

■ Automatic Antenna Tuning: The CYW4354 has an on-chip automatic antenna tuning network. When used with a single off-chip

inductor, the on-chip circuitry automatically chooses an optimal on-chip matching component to obtain the highest signal strength

for the desired frequency. The high-Q nature of this matching network simultaneously provides out-of-band blocking protection as

well as a reduction of radiated spurious emissions from the FM antenna. It is designed to accommodate a wide range of external

wire antennas.

8.9 RDS/RBDS

The CYW4354 integrates a RDS/RBDS modem and codec, the decoder includes programmable filtering and buffering functions, and

the encoder includes the option to encode messages to PS or RT frame format with programmable scrolling in PS mode. The RDS/

RBDS data can be read out in receive mode or delivered in transmit mode through either the HCI interface.

In addition, the RDS/RBDS functionality supports the following:

Receive

■ Block decoding, error correction and synchronization

■ Flywheel synchronization feature, allowing the host to set parameters for acquisition, maintenance, and loss of sync. (It is possible

to set up the CYW4354 such that synch is achieved when a minimum of two good blocks (error free) are decoded in sequence. The

number of good blocks required for sync is programmable.)

■ Storage capability up to 126 blocks of RDS data

■ Full or partial block B match detect and interrupt to host

■ Audio pause detection with programmable parameters

■ Program Identification (PI) code detection and interrupt to host

■ Automatic frequency jump

■ Block E filtering

■ Soft mute

■ Signal dependent mono/stereo blend

■ Programmable pre-emphasis

BCM4354 Datasheet(PDF) 47 Page - Cypress Semiconductor