Specifications

WA_DEV_FEX20_PTS_004 Rev 001 June 30, 2010 28
Expansion Card Product Technical
Specification
Interfaces
Table 19: External Antenna Characteristics
Antenna Frequency Range
1.57542GHz ± 1.023MHz (L1-Band)
Impedance
50Ω nominal
Voltage Supply
3.3V ± 0.5VDC
Gain (antenna + cable)
2dBi (typical)
4.7. Digital Audio Interface (PCM)
The Digital Audio Interface (PCM) interface allows connectivity with standard audio peripherals. It can
be used, for example, to connect an external audio codec.
The programmability of this mode allows addressing a large range of audio peripherals.
The signals used by the Digital Audio Interface (PCM) are as follows:
 PCM-SYNC (output): The frame synchronization signal delivers an 8KHz frequency pulse that
synchronizes the frame data-IN and the frame data-OUT.
 PCM-CLK (output): The frame bit clock signal controls data transfer with the audio peripheral.
 PCM-OUT (output): The frame “data-OUT” relies on the selected configuration mode.
 PCM-IN (input): The frame “data-IN” relies on the selected configuration mode.
The Digital Audio Interface has the following features:
 IOM-2 compatible device on physical level
 Master mode only with 6 slots by frame, user only on slot 0
 Bit rate single clock mode at 768KHz only
 16 bits data word MSB first only
 Linear Law only (no compression law)
 Long Frame Synchronization only
 Push-pull configuration on PCM-OUT and PCM-IN
Note that the digital audio interface configuration cannot differ from those specified above.
4.7.1. Waveforms
The following figures describe the PCM Frame and Sampling waveforms.