AM6442: How to configure Multiple Chip Select for GPMC/OSPI in sysconfig

Hello Yuto Kitamura,

Currently, in MCU+SDK, we do support only one CS.

As per the TRM, SOC can support 4 CS lines and each CS line has its own memory type and memory timing parameters.

So, if you need more CS confirmation, which is not possible in system cfg.

Users need to do manually similar as how 1CS configuration is done by the generated code.

When enabling 4 CS lines are connected to GPMC and not tested at TI side and users need to take consideration of PCB routing.

Please look at the FAQ below which tells you about the what are the maximum size can be connected to GPMC.

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1349234/faq-am24x-am64x-am62x-what-are-the-maximum-sizes-of-nand-or-nor-or-psram-memories-that-can-be-connected-to-gpmc-for-the-am24x-am64x-am62x

Hi Anil,

Thanks for support.We will review the FAQ for GPMC.

How about OSPI multi CS configuration? Do we have the sample code?

And do we have plan to release sysconfig update to support multiple CS configuration?

Best regards,

Yuto

Hello,

Yuto Kitamura said:

How about OSPI multi CS configuration? Do we have the sample code?

And do we have plan to release sysconfig update to support multiple CS configuration?

The support is currently not there for OSPI for for MCSPI for multiple CS lines.

You can expect responses in sometime from my end.

Regards,

Vaibhav

Hello Yuto,

Currently the TI drivers for OSPI is written in such a way that it supports 1 CS line, hence in the SysConfig window does not have options to add multiple CS lines and pair them up with more than one flash parts.

A SW workaround can be implemented to make sure that you have more than one, lets say two flash parts and your single piece of software is taking care of switching between interacting with flash part 1 and 2 based on certain checks.

Regards,

Vaibhav

Hi Vaibhar,

Would you please share me the sample code of "software workaround" you mentioned? They need 4 parts to be controlled. 

Vaibhav Kumar said:

A SW workaround can be implemented

Best regards,
Yuto Kitamura

Hello Yuto,

Before sharing a sample piece of code, let me write down the logic first.

So let's assume currently there are two flash parts connected and you have one SW code to change between two flash parts to do the write/read operations.

So the first thing we can do is switch between the flash parts based on the condition that every flash has different device id and manufacture id. So we can do the following:

At first let's say we do not know which CS line is being in effective, then, we need to follow the below steps:

1. Reset the current addressed flash part
2. Resetting refers to setting the flash part to 1s-1s-1s mode
3. Now send few commands and get the flash part's device id and manufacture id
4. Based on the device id and manufacture id, initialize the flash configuration parameters
5. Also based on the condition in Step 4, do the write/read operations accordingly.

Let me know if the above logic resonates with you?

Regards,

Vaibhav

Hi Vaibhav,

Thanks for respond back. Let me make sure that is this logic can be used for 4 flash configuration? I mean does AM6442 technically support 4 flash (OSPI interface) system?

Best regards,
Yuto

Hello Yuto,

Yuto Kitamura said:

I mean does AM6442 technically support 4 flash (OSPI interface) system?

Please read through the following section: https://www.ti.com/document-viewer/lit/html/SPRUIM2H#GUID-59ECEA4E-67C7-401B-A4A5-6AD66731B6BD/TITLE-SPRUIM2INT_SPRUIJ7_INIT_000462

Regards,

Vaibhav

Hi Vaibhav,

I saw 4.4.1.2 xSPI Boot and understood it supports 4 CS config technically. 

And I will mentions to developer what you mentioned. So would you please provide the config code for 4CS setting?

Vaibhav Kumar said:

So the first thing we can do is switch between the flash parts based on the condition that every flash has different device id and manufacture id

best regards,
Yuto

Wait for the update. thank you.

Hello Yuto,

Thanks for your patience.

May I know which flash part you are using, as in is it a NAND or a NOR Flash Part?

Then I can provide you with a sample code/logic for you to test out.

Looking forward to your response.

Regards,

Vaibhav

Hi Vaibhav,

- We use NOR flash for all 4CS.
- 3 same P/N and 1 another P/N flash will be used.
- All devices will be used with 1s-1s-1s protocol.

Wait for your support of sharing sample code.

Thank you.
yuto

Hello Yuto,

Allow me sometime to provide you with the code for the same.

Regards,

Vaibhav

Hi Vaibhav,

Thank you! We are looking forward to your update.

yuto

Hello,

I have written a code which you can go ahead and test out at first.

So the OSPI controller will address one flash part/one CS line at one time.

void ospi_switch_flash_parts(void *args)
{
    int32_t status = SystemP_SUCCESS;
    uint32_t manfId, deviceId;

    /* Open OSPI Driver, among others */
    Drivers_open();

    OSPI_Handle ospiHandle = OSPI_getHandle(CONFIG_OSPI0);

    /* Zero init the dev defines struct */
    memset(&gNorSpiDevDefines, 0, sizeof(gNorSpiDevDefines));

    OSPI_norFlashSetCmds(0x03, 0x02, 0xD8);

    /* Initialize the flash device in 1s1s1s mode */
    OSPI_norFlashInit1s1s1s(ospiHandle);

    /* Read ID */
    status = OSPI_norFlashReadId(ospiHandle, &manfId, &deviceId);

    if(SystemP_SUCCESS == status)
    {
        DebugP_log("[OSPI Flash Diagnostic Test] Flash Manufacturer ID : 0x%X\r\n", manfId);
        DebugP_log("[OSPI Flash Diagnostic Test] Flash Device ID       : 0x%X\r\n", deviceId);

        gNorSpiDevDefines.manfId = manfId;
        gNorSpiDevDefines.deviceId = deviceId;
	// Now based on the flash part's manufacture and device id you can initialize the flash parameters and do the corresponding flash operations
	// condition can be as follows
	if(manfId == flashPart1manfId && deviceId == flashPart1deviceId){
              // initialize the flashPart1 parameters
	      // do the operations for flashPart1
        }
         .... // similar initialization and operations for flashPart2
         .... // similar initialization and operations for flashPart3
    }

Let me know if you need further clarifications.

Regards,

Vaibhav