pnx1500 NXP Semiconductors, pnx1500 Datasheet - Page 98

• Manufacturer Part Number: pnx1500
• Description: Pnx15xx Series Connected Media Processor
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Volume 1 of 1
8. Audio processing and Input/Output
PNX15XX_SER_3
Product data sheet
8.1 Audio Processing
8.2 Audio Inputs and Outputs
Motion vectors computed by TM3260 software can be sent to a video improvement
post-processor over the PCI interface.
The function of VDO_AUX is programmed using the QVCP capability to combine
alpha or chroma-keying information during blending. For example, chroma keys in a
graphics plane could be used to drive VDO_AUX. For another example, a threshold
value for an alpha value of a graphics plane could be used to indicate whether a pixel
is more than 80% video.
All audio processing in PNX15xx Series is performed in software on the TM3260.
This includes decoding of audio from compressed formats, sample rate conversion,
mixing and special effects processing. There is sufficient performance, if required, to
transcode received audio to multi-channel compressed audio sent over S/PDIF to an
attached receiver.
The PNX15xx Series has several Audio Input/Output facilities:
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PNX15xx Series Audio In can capture up to 8 stereo audio inputs with up to 32-
bit/sample precision at sample rates up to 96 kHz. Both Audio In and Audio Out
support most A/D converter serial protocols, including I
internally or externally generated. The internal generator is programmable with
sub one Hertz sampling rate accuracy. Audio In also includes a raw mode which
allows the capture of any quantity of bits out of the programmable frame (up to
512 bits per frame). The word strobe (AI_WS pin) is also captured and stored into
memory.
PNX15xx Series Audio Out can generate up to 8 channels of audio, and directly
drives up to 4 external stereo I
bit/sample precision at sample rates up to 96 kHz. The sample rate can be
internally or externally generated. The internal generator is programmable with
sub one Hertz sampling rate accuracy. Audio out does not include a raw mode as
the Audio In module does.
PNX15xx Series supports a SPDIF (Sony Philips Digital Interface) output with
IEC-1937 capabilities. Transmitted data is generated by TM3260 software. This
output port can carry either stereo PCM samples from an internal audio mix, or
one of the originally received compressed audio programs (5.1 channel AC-3,
multi-channel MPEG audio, multi-channel AAC). Sample rate of transmitted
audio is set by software, allowing perfect synchronization to any time reference in
the system.
PNX15xx Series supports a SPDIF input to connect to external sources, such as
a DVD player. The incoming data is timestamped and written to unified system
memory. Data interpretation and sample rate recovery is achieved by software on
the TM3260. The audio data received can be in a variety of formats, such as
stereo PCM data, 5.1 channel AC-3 data per IEC-1937 or other. Software
Rev. 3 — 17 March 2006
2
S or similar D/A converters. It supports up to 32-
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
PNX15xx Series
2
S. Sample rate is
Chapter 2: Overview
2-17