Smart Machine Smart Decision
Table 20: PCM specification
Parameter
Specification
Line Interface Format
Linear(Fixed)
Data length
8/16bits
PCM Clock/Sync Source
Slave/Master Mode
PCM Clock Rate
256Khz
、
2.048Mhz
Data Ordering
MSB/LSB both support
4.8.1.
PCM Multiplexing Function
The following table shows the detailed multiplexing function.
Table 21: PCM multiplexing function
Pin name
Pin number
Mode 0(default)
Mode 1
PCMCLK
11
PCMCLK
GPIO8
PCMIN
12
PCMIN
GPIO9
PCMOUT
13
PCMOUT
GPIO10
PCMSYNC
14
PCMSYNC
GPIO11
Note: Multiplexing function needs different software supply.
4.8.2.
PCM Interface
Refer to the following figure for PCM design:
Figure 28: PCM reference circuit
4.8.3.
Auxiliary PCM (128 KHz PCM clock)
u-law coding is supported by the auxiliary PCM. The auxiliary codec port operates with standard long-sync
timing and a 128 KHz clock. The PCMSYNC runs at 8 KHz with 50% duty cycle. Most u-law codec support the
128 KHz clock.
Figure 29: Synchrony timing
SIM2000S_Hardware_Design_V1.00
35
2014-02-27