FS
DX
CLK
MSB
15
14
LSB
2
3
0
1
MSB
15
14
LSB
2
3
0
1
DR
Padding bits to 0
Dummy bits
MSB
15
14
LSB
2
3
0
1
15
14
2
3
0
1
MSB
LSB
Padding bits to 0
Dummy bits
mcbsp-014
FS
DX
CLK
MSB
15
14
LSB
2
3
0
1
MSB
15
14
LSB
2
3
0
1
DR
Padding bits to 0
Dummy bits
MSB
15
14
LSB
2
3
0
1
15
14
2
3
0
1
MSB
LSB
Padding bits to 0
Dummy bits
mcbsp-015
Public Version
McBSP Environment
www.ti.com
21.2.4.4 Voice Protocol and Data Formats
21.2.4.4.1 Protocol
The PCM protocol is intended to transfer voice data at 8 kHz (default narrowband mode) or 16 kHz
(wideband mode) sample rates (frame-sync frequency). PCM protocol can act as a slave or master, and is
used by the Bluetooth interface and the modem generic interface. The frame-synchronization defines the
frame length in the PCM protocol. Bits are clocked using PCM clock signal, with MSB first.
21.2.4.4.2 Data Formats
Two modes are available for the PCM protocol: mode 1 and mode 2. For these both modes, it has two
types of operations: Mono or stereo channels. The difference between PCM mode 1 and PCM mode 2 is
in the way they use either the rising or the falling edge of clock signal, and the frame-synchronization
polarity.
•
PCM Mode 1: Input data is latched on the falling edge of the clock, and the transmitted data starts on
the rising edge of the clock. Frame-synchronization pulse is active high.
•
PCM Mode 2: Input data is latched on the falling edge of the clock, and the transmitted data starts on
the falling edge of the clock. Frame-synchronization pulse is active low.
and
shows an example of PCM protocol, mode 1 and mode 2, respectively, for
a frame composed one word (width: 32 bits) with 16 bits data.
Figure 21-14. PCM Protocol - Mode 1 Data Format
Figure 21-15. PCM Protocol - Mode 2 Data Format
3068
Multi-Channel Buffered Serial Port
SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated
Содержание OMAP36 Series
Страница 174: ...174 List of Tables SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 692: ...692 MPU Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 1084: ...1084 IVA2 2 Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 1990: ...1990 2D 3D Graphics Accelerator SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2334: ...2334 Memory Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2700: ...2700 Memory Management Units SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2868: ...2868 HDQ 1 Wire SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2974: ...2974 UART IrDA CIR SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3054: ...3054 Multichannel SPI SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3462: ...3462 MMC SD SDIO Card Interface SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3508: ...3508 General Purpose Interface SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3584: ...3584 Initialization SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3648: ...3648 Debug and Emulation SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...