PNX1502E Datasheet, PDF (527/828 Pages) NXP Semiconductors – Connected Media Processor

Chapter 16: Audio Input
PNX15xx/952x Series Data Book – Volume 1 of 1
Rev. 4.0 — 03 December 2007
Product data sheet
1. Introduction
The Audio Input block can have up to four audio input ports. Each audio input port
supports single or dual-channel sources. Hence the Audio In block can support up to
8 channels of audio input (4 stereo channels).
The Audio In module provides a DMA-driven serial interface to an off-chip stereo A/D
converter, I²S subsystem or other serial data source. Audio In provides all signals
needed to connect to high quality, low cost oversampling A/D converters. The Audio
In module and external A/D converter (or I²S subsystem) together are capable of
generating a programmable sample clock by dividing a precise oversampling clock,
which is an input to this block. It is assumed that a programmable clock generator for
a precise oversampling A/D system clock is present elsewhere in the chip.
1.1 Features
• Four channels of audio input per port
• 16 or 32-bit samples per channel
• Programmable 1 Hz to 100 kHz sampling rate
(Note: This is a practical range. The actual sample rate is application dependent.)
• Internal or external sampling clock source
• Audio In autonomously writes sampled audio data to memory using buffering
(DMA)
• 16-bit and 32-bit mono and stereo PC standard memory data formats
• Raw mode where the bits from all the active inputs are sampled by bit clock along
with the frame sync signal (WS) and packed into one 8 bit byte in memory for
software to tear apart.
• Little or big-endian memory formats.
Remark: AC-97 codecs are not supported.