Cypress S6J3200 Series, Manual

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CHAPTER 26:PCMPWM
980 S6J3200 Series Hardware Manual Document Number: 002-04852 Rev. *G
Mono or Stereo Mode
The PCMPWM module supports two modes of driving the two output channels – mono and stereo. In
mono mode a single stream of PCM data samples is used to drive both output channels. I.e. both
conversion units use the same PCM sample data values. Mono mode alternates between the lower (used
first) and the upper 16 bits of the PCM data sample word. Thus the effective depth of the FIFO buffer
increases to 48. Figure 2-5 depicts the data transfer from the FIFO buffer to the PCM to PWM conversion
units in mono mode.
Figure 2-5 Mono Mode
In stereo mode each PCM sample consists of a pair of values for the two channels. They are written to
the module at the same time but the values for both channels are independent of each other. The lower
16 bits of the sample word are used for channel #0 and the upper 16 bits are used for channel #1. Mono
or stereo mode is configured with the PCMPWMi_CONTROL:STEREO bit. Figure 2-6 depicts the data
transfer from the FIFO buffer to the PCM to PWM conversion units in stereo mode.
Figure 2-6 Stereo Mode
data[31:16]
Conversion
Unit Ch #1
Conversion
Unit Ch #0
data[15:0]
FIFO Buffer
data[31:16]
Conversion
Unit Ch #1
Conversion
Unit Ch #0
FIFO Buffer
data[15:0]
Conversion
Unit Ch #1
Conversion
Unit Ch #0
data[15:0]
FIFO Buffer
data[31:16]