cs7410 Cirrus Logic, Inc., cs7410 Datasheet - Page 21

• Manufacturer Part Number: cs7410
• Description: Cd/mp3/wma Audio Controller
• Manufacturer: Cirrus Logic, Inc.

3.5
The system control functions are used to coordinate the activities of the multiple processors, and to pro-
vide the supporting system operations. Two 32-bit communication registers are available for inter-proces-
sor communication, and 32 semaphore registers are used for resource locking. Three timers are available
for general-purpose functions, as well as more specialized functions, such as watchdog timers and per-
formance monitoring.
The large number of general purpose I/Os offers flexibility in system configurations. Three separate syn-
chronous serial interfaces, conforming to industry-standard protocols, are available for a variety of system
interface functions. Four general purpose software interrupts and twelve hardware interrupts help reduce
peripheral overhead and improve UI responsiveness. Power-down control of the internal clocks is also
possible. An internal PLL is used to generate the internal system and memory clocks as well as audio
clocks for all supported sample rates.
3.6
Decoded audio data is written into an output FIFO in 16-, 18-, 20- or 24-bit PCM format. A flexible audio
output stage can simultaneously output 4 channels of PCM data to external audio DACs, plus an inde-
pendent IEC-958 encoded output. The IEC-958 output has fully programmable channel status (commer-
cial), and provides a flexible solution to support all IEC-958 modes for user data. The audio output circuit
contains an auto-mute detect circuit, which can generate internal or external mute controls
PCM FIFO data up to 18 bits can also be output by the on-board sigma-delta stereo modulator. The sig-
ma-delta modulator yields a typical 85 dB signal-to-noise ratio with few external components required, re-
sulting in a low-cost, low parts count analog front end. The modulator has a 32x upsampling filter, followed
by a 32x interpolator, and finally a 5
the modulator output, and there are separate programmable attenuators for the modulator output and
both PCM outputs.
DS553PP3
System Control Functions
Audio Output
th
-order Sigma-Delta modulator. The auto-mute circuit also works on
CS7410
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