AM3352: Asynchronous Multiple (Page Mode) Read Operation on a Nonmultiplexed Device: A sample code

Hideaki Nambu

Part Number: AM3352

Hello,
Please find the following chapter from the TRM SPRUH73 :

7.1.2.3.10.3.3 Asynchronous Multiple (Page Mode) Read Operation on a Nonmultiplexed Device

My customer need four or more data phase per access.
They built their own board and trying to access an FPGA. It is not successful.

Then, is there a sample code available for this access to show a proven procedure?

Or, could you please tell us a configuration to have the page mode access ?

Is it neccesary to use the FIFO in the GPMC subsystem? Is it possible to do that without DMA?
Is it necessary to use the DMA? Is it possible to do that without FIFO mentioned above?

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

Hi,

What software are you using? Linux or TI-RTOS? Which version?

0 Hideaki Nambu over 6 years ago in reply to Biser Gatchev-XID

Mastermind 9165 points

Biser,
Thank you for your response.
They use Processor-sdk-rtos-am335x-4.2.0. Actually No-OS.

0 Biser Gatchev-XID over 6 years ago in reply to Hideaki Nambu

TI__Guru**** 393215 points

Thanks. I have asked the RTOS team to comment. They will respond here.

0 lding over 6 years ago in reply to Biser Gatchev-XID

TI__Guru* 95265 points

Hi,

We have GPMC over NOR example for AM335x. The NOR is Micron M29W160EB, this is Nonmultiplexed and Asynchronous. You may refer to the GPMC test example under pdk_am335x_1_0_12\packages\ti\drv\gpmc

Regards, Eric

0 Hideaki Nambu over 6 years ago

Mastermind 9165 points

Part Number: AM3352

Hello,
Thank you very much for my previous thread: https://e2e.ti.com/support/processors/f/791/p/746913/2759448#2759448

Actually my customer is trying to raise the GPMC bandwidth under "Asynchronous, MULTIPLEXED, Read operation".
Could you please give your advise to the followings?:

Q. Is it possible for EDMA or any other ways to shorten the gpmc access interval like 260nsec? The time 260nsec was brought from the thread: https://e2e.ti.com/support/processors/f/791/t/331886

Q. I think the page mode is not possible under "Asynchronous, MULTIPLEXED, Read operation" even if the EDMA or FIFO-prefetch, or both are used. Is it correct ?

I am discussing with my customer about a sentence in the thread:
"Without prefetch and DMA, you will get only about 2MBytes/sec."
https://e2e.ti.com/support/processors/f/791/t/331886

edit> My customer use Processor-sdk-rtos-am335x-4.2.0. Actually No-OS.

0 Hideaki Nambu over 6 years ago

Mastermind 9165 points

Part Number: AM3352

Hello,

Please find the following chapter from the TRM SPRUH73 :

7.1.2.3.10.3.3 Asynchronous Multiple (Page Mode) Read Operation on a Nonmultiplexed Device

They use Processor-sdk-rtos-am335x-4.2.0. Actually No-OS.

My customer FPGA asserts a signal to request a GPMC page mode transfer.

Could you please advise how to detect the request and start the transfer?

A possible way for AM3352 would be to input the signal by a GPIO, trigger an IRQ, then the ISR firmware will start GPMC.

Is there a faster way to start, like a hardware scheme to trigger GPMC?

0 lding over 6 years ago in reply to Hideaki Nambu

TI__Guru* 95265 points

Hi,

Is that correct that FPGA needs to signal the AM335x that data is ready for transfer? If yes, GPIO approach you mentioned above is efficient to trigger such an transfer.

Regards, Eric

0 Hideaki Nambu over 6 years ago in reply to lding

Mastermind 9165 points

Iding,
Thank you for your reply to the latest question.
By the way, the previous questions are also necessary for us. Please give your comment. Thank you very much.

Copy from a post on 2018/11/16 7:08 pm

My customer use Processor-sdk-rtos-am335x-4.2.0. Actually No-OS.
They are trying to raise the GPMC bandwidth under "Asynchronous, MULTIPLEXED, Read operation".
Could you please give your advise to the followings?:

Q. Is it possible for EDMA or any other ways to shorten the gpmc access interval like 260nsec? The time 260nsec was brought from the thread: https://e2e.ti.com/support/processors/f/791/t/331886

Q. I think the page mode is not possible under "Asynchronous, MULTIPLEXED, Read operation" even if the EDMA or FIFO-prefetch, or both are used. Is it correct ?

I am discussing with my customer about a sentence in the thread:
"Without prefetch and DMA, you will get only about 2MBytes/sec."
https://e2e.ti.com/support/processors/f/791/t/331886