TMS320C6746: About Audio Pre-processing issue

yimin bai34

Genius 4755 points

Part Number: TMS320C6746
Other Parts Discussed in Thread: OMAP-L132, TMS320C6742

Hi SIr

We would like to use C6747 to do audio pre-processing, TI has offer CMB/LMB reference to connect to TI DSP platform.

We would like to connect below microphone array to C6746 which can support TMD,

We found it only support WS/SD/SCK pin to connect to TI DSP. It seems this array support serial audio output.

Does TI C6000 can support this kind of format ?

According to MCASP's description, C6000 MCASP should connect to multi- AXR[x] pins.

please advise

Yimin

over 7 years ago

0 Lalindra Jayatilleke over 7 years ago

TI__Mastermind 30365 points

yimin,

Yes, this should work on C674x.
If I understand correctly, the 4 mics are chained together and output 1 I2S stream to the C674x?
Please see e2e.ti.com/.../171412

Lali

0 yimin bai34 over 7 years ago in reply to Lalindra Jayatilleke

Genius 4755 points

Hi Sir

thanks for your reply.

Do we use MCASP or MCBSP to connect the I2C stream from Mics array which chained together and output

BR
Yimin

0 Lalindra Jayatilleke over 7 years ago in reply to yimin bai34

TI__Mastermind 30365 points

Yimin,,

You can use the McASP to connect the mics to the C674x.

Lali

0 yimin bai34 over 7 years ago in reply to Lalindra Jayatilleke

Genius 4755 points

Hi Sir

thanks for your reply.

there are three pins (WS/SD/SCK) coming from Microphone array and there is one I2S signal coming from Amplifier.

Do you know how to do the pinmux ? any specific pins need to be configured ?

BR
Yimin

0 Mark M over 7 years ago in reply to yimin bai34

TI__Mastermind 30170 points

Hi Yimin,

Pin multiplexing can be controlled on a pin-by-pin basis. Device level pin multiplexing is controlled by registers PINMUX0 - PINMUX19 in the SYSCFG module. I recommend you use the OMAP-L132/L138, TMS320C6742/6/8 Pin Multiplexing Utility (Rev. B)

http://www.ti.com/lit/pdf/sprab63

I have attached a sample .pin file for this tool that configures only AXR0, AFSR, and ACLKR as muxed pins.

/cfs-file/__key/communityserver-discussions-components-files/791/only--AXR0_2C00_-ACLKR_2C00_-AFSR-selected.pin

McASP0

AXRn --> SD (Can use AXR0, but any of the AXR0 - AXR15 pins should work

AFSR --> WS (only receiving, so AFSR should be output to the mic)

ACLKR --> SCK (only receiving, so ACLKR should be output to the mic)

Does the microphone require a pulse (1-bit wide) for the WS strobe? TDM typically sends this kind of a pulse to signal the start of a frame. Then it counts bit clocks to distinguish between the 4 TDM channels being received from the microphone.

What frame clock frequency are you planning to use? You may need to select a crystal or oscillator that can support that frequency with integer multiplier and divider offered by the on-chip PLL.

Regards,
Mark

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TMS320C6746: About Audio Pre-processing issue