AM6442: AM642 GPMC qustions

Hello Lina,

You can expect reply by EOD .

Regards,

Anil.

Hello Lina,

lina zhang said:

1、asynchronous brust write not support？

Please look at the PSRAM ISSI datasheet.

Most of the PSRAM memories does not allow the page write operation and it only supports the page read operation.

So, GPMC peripherals also do not support this feature.

https://www.issi.com/WW/pdf/66-67WVE4M16EALL-BLL-CLL.pdf

lina zhang said:

2、how to configure GPMC FCLK in uboot

GPMC will be used in Application. So, GPMC clock initializations should be done in Application.

Why do you wanted to run in u boot rather than Application ?

lina zhang said:

how to configure asynchronous brust read （page read ）RDCYCLETIME0 RDCYCLETIME1 CSRDOFFTIME0 CSRDOFFTIME1  OEOFFTIME0 OEOFFTIME1 in the below picture？

As per TRM, we do support page read mode but how does GPMC know read operation is normal operation or Page Read .

I need some more time to get back on this .

Regards,

Anil.

2、how to configure GPMC FCLK in uboot

------in the application，wo dont have the gpmc driver ，so we need to use the GPMC driver in the uboot to configure the gpmc

-------we want to configure the gpmc FCLK from 133M to 125M，how？

Hi,

I have routed this query to the GPMC expert for further comments.

Regards,
Aparna

Hi Lina,

It appears GPMC FCLK can come from one of two sources:

- MAIN_0_HSDIVOUT3 which supports 133MHz, 100MHz, 80MHz
- MAIN_2_HSDIVOUT7, which supports 100MHz, 60MHz

None of them can be configured to 125MHz.

Why do you need the GPMC FCLK to run at 125MHz?