S3C2416X RISC MICROPROCESSOR
PCM AUDIO INTERFACE
25-3
3 PCM
TIMING
The following figures show the timing relationship for the PCM transfers.
Figure 25-1 shows a PCM transfer with the MSB configured to be coincident with the PCMFSYNC. This MSB
positioning corresponds to setting the TX_MSB_POS and RX_MSB_POS bits in PCMCTL register to be 0.
PCMFSYNC
PCMSOUT
14
15
13
1
0
dont care
15
14
. . .
output
output
output
PCMSCLK
input
pcm_irq
(sync to DSP clk)
14
15
13
1
0
dont care
15
14
. . .
input
internal
PCMSIN
PCMSOURCE_CLK
datain_reg_valid
Figure 25-1. PCM timing, TX_MSB_POS / RX_MSB_POS = 0
Figure 25-2 shows a PCM transfer with the MSB configured one shift clock after the PCMFSYNC. This MSB
positioning corresponds to setting the TX_MSB_POS and RX_MSB_POS bits in PCMCTL register to be 1.
PCMFSYNC
PCMSOUT
15
14
1
0
dont care
15
. . .
output
output
output
PCMSCLK
input
pcm_irq
(sync to DSP clk)
15
14
1
0
dont care
15
. . .
input
internal
PCMSIN
PCMSOURCE_CLK
datain_reg_valid
Figure 25-2. PCM timing, TX_MSB_POS / RX_MSB_POS = 1
NOTE
In all cases, the PCM shift timing is derived by dividing the input clock, PCMSOURCE_CLK. While the timing is based
upon the PCMSOURCE_CLK, there is no attempt to realign the rising edge of the output PCMSCLK with the original
PCMSOURCE_CLK input clock. These edges will be skewed by internal delay through the pads as well as the divider
logic. This does not represent a problem because the actual shift clock, PCMSCLK, is output with the data.
Furthermore, even if the PCMSCLK output is not used, the skew will be significantly less than the period of the
PCMSOURCE_CLK and should not represent a problem since most PCM interfaces capture data on the falling edge
of the clock.
Summary of Contents for S3C2416
Page 122: ...BUS MATRIX EBI S3C2416X RISC MICROPROCESSOR 3 4 NOTES ...
Page 204: ...DMA CONTROLLER S3C2416X RISC MICROPROCESSOR 8 18 NOTES ...
Page 284: ...WATCHDOG TIMER S3C2416X RISC MICROPROCESSOR 11 6 NOTES ...
Page 320: ...REAL TIME CLOCK S3C2416X RISC MICROPROCESSOR 13 16 NOTES ...
Page 344: ...UART S3C2416X RISC MICROPROCESSOR 14 24 NOTES ...
Page 380: ...USB2 0 DEVICE S3C2416X RISC MICROPROCESSOR 16 34 NOTES ...
Page 432: ...2D S3C2416X RISC MICROPROCESSOR 18 38 NOTES ...
Page 446: ...HS_SPI CONTROLLER S3C2416X RISC MICROPROCESSOR 19 14 NOTES ...
Page 604: ...S3C2416X RISC MICROPROCESSOR S3C2416X RISC MICROPROCESSOR 23 22 NOTES ...
Page 638: ...PCM AUDIO INTERFACE S3C2416X RISC MICROPROCESSOR 25 18 NOTES ...
Page 670: ...ELECTRICAL DATA S3C2416X RISC MICROPROCESSOR 26 32 NOTES ...