Trouble accessing McASP XBUF/RBUF via DATAPORT on DM8168 device

james conway

Hi,

I'm debugging McASP/EDMA driver code that runs on the 6748 DSP core of a DM8168 device.

I unable to find McASP2's receive/transmit buffer DMA port address that is accessed when the bus-select bits (XBUSEL and RBUSEL) of the XFMT/RFMT register is cleared.

The 8168 datasheet indicates McASP2 at address 0x46800000 in the L3 and Cortex-A8 Memory Map tables. I've tried using this address as the XBUF/RBUF Data port when I configure EDMA, but have not been able to get data flowing out the McASP. Can anyone verify whether the address I'm using is correct, and if not, what the actual one is?

Thanks,

Jim

over 13 years ago

0 David Friedland over 13 years ago

TI__Mastermind 18320 points

Jim,

This appears to be a device specific question rather than really related to BIOS, so I have moved this thread in hopes that it will get a faster response there.

Dave

0 MarcPyne over 13 years ago

TI__Mastermind 25055 points

Jim,

Are you using the Peripheral Register addresses as found in the McASP0, McASP1, and McASP2 Peripheral Register Descriptions table in the device datasheet?

Regards,
Marc

0 james conway over 13 years ago in reply to MarcPyne

Intellectual 780 points

Marc,

Yes, but the address of the XBUF/RBUF when accessed through the data port is not listed. If you look at table 14-8 of the Technical Reference: (SPRUGX8–1 July 2011), it references the data port, but does not provide an address offset. Similarly, table 8-76 of the datasheet: (SPRS614A–MARCH 2011–REVISED AUGUST 201) has no entry for the XBUF/RBUF when accessed via the data port.

Other device documentation, such as the Omap L-138 datasheet and technical reference, explicitly states the address I'm looking for. This leads me to believe that there's an oversight in the DM816x documentation.

Thanks,

Jim

0 MarcPyne over 13 years ago in reply to james conway

TI__Mastermind 25055 points

Jim,

Hmmm... Good point. I will look into it.

Regards,
Marc

0 Andrew Elder over 13 years ago in reply to MarcPyne

Expert 1680 points

Was this ever resolved? I'm looking for same for 814x.

0 Andrew Elder over 13 years ago in reply to Andrew Elder

Expert 1680 points

Following up on my own post, it looks like the L3 address of 0x46002000u works for programming MCASP0_RXBUF into the DSP's EDMA.

0 MarcPyne over 13 years ago in reply to Andrew Elder

TI__Mastermind 25055 points

Sorry for the confusion. The latest TRM revision has an update on this, and the next datasheet revision will have the register descriptions changed from just “McASPx” to “McASPx Data Peripheral Registers”. The note added in the TRM refers to the data peripheral addresses in the L3 table in the device data sheet.

Regards,
Marc

0 Andrew Elder over 12 years ago in reply to MarcPyne

Expert 1680 points

I just picked up the latest datasheet and still no obvious definition of RBUF address to use when programming EDMA.

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Trouble accessing McASP XBUF/RBUF via DATAPORT on DM8168 device