User Manual

Iridium Communications, Inc. Information Contained in this Guide
Iridium 9523 Product Developers’ Guide is Subject to Change Without Notice
Revision 2.6
Iridium Communications, Inc. Distribution of Guide Restricted
Proprietary & Confidential Information Page 25 of 115 to Product Developers
Only
The PCM data input has set-up and hold time requirements of 30 ns with respect to the falling edge of the
PCM clock signal.
The two PCM ports were originally intended to be connected to a voice source/sink via a codec (such as
the Texas Instruments TLV320AIC1110) for analog audio and directly for digital audio, but there is no
need to use them in this way.
Figure 9 - PCM waveform diagram
3.3.1 Port 1
Port 1 has the following signal pins:
Table 9: PCM Port 1 Signals
Signal function Signal name
PCM clock output CODEC_PCMCLK
PCM sync output CODEC_PCMSYNC
PCM data output CODEC_PCMIN
PCM data input CODEC_PCMOUT
Note: the data signal names on Port 1 are defined from the point of view of an externally connected
codec.
3.3.2 Port 2
Port 2 has the following signal pins:
Table 10: PCM Port 2 Signals
Signal function Signal name
PCM clock output UC_DACLK
PCM sync output UC_DAFS
PCM data output UC_DATX
PCM data input UC_DARX
Note: the data signal names on Port 2 are defined from the point of view of the Iridium 9523.
3.3.3 11Hz Signal for Manufacturing and Regulatory Testing
An external ‘frame tick’ signal needs to be passed to the Iridium 9523 during regulatory radio testing of
the host system, and possibly also during manufacturing testing. This frame signal has a period of 90ms
(11.1Hz) and is fed to the Iridium 9523 using the CODEC_PCMOUT PCM data input.
PCM clock
PCM sync
PCM output
PCM input
1 (msb)
23
15
16 (lsb)
1 (msb)
23
15 16 (lsb)
4
4