SK-AM68: VMAP in bypass mode

Isee

Part Number: SK-AM68

In the DMA documentation there is VMAP unit and it stated that it can be configured to work in bypass mode. With this mode UDMA can make transactions to main PC memory, not only mapped addresses. This feature is supported in HW but not in Linux

Can you porvide a detailed documentation for all registers concerning PCIe and UDMA modules?

11 months ago

0 Isee 11 months ago

TI__Expert 4850 points

Reminder

0 B.C. 11 months ago in reply to Isee

TI__Genius 15505 points

The register descriptions are provided in the XLS file that is zipped up with the TRM PDF.

0 Isee 11 months ago in reply to B.C.

TI__Expert 4850 points

we know about XLS file, but to program it we need more than this.
How to get access to documentation?

0 B.C. 11 months ago in reply to Isee

TI__Genius 15505 points

The register XLS file and TRM UDMA and PCIe chapters are the available documentation.

0 jian35385 10 months ago in reply to B.C.

TI__Mastermind 23125 points

Isee,

We assumed you are trying to bypass the PCIe address translation by using VMAP to directly map to the PC side memory. This is acutely not supported by software presently. The TRM has the information, but software was never implemented due to lack of use cases.

Please use the standard address translation by programming multiple regions. If you need many segmented address windows, you can program a larger region then use multiple buffers within the region. You can use the PCIex_DAT1 region if you need large address ranges, these can be up to 32GB. Note these addresses are in 40-bit SOC address space.

Regards

Jian

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SK-AM68: VMAP in bypass mode