Am 2021-03-12 11:17, schrieb Pratyush Yadav:
On 12/03/21 09:13AM, Tudor.Ambarus@xxxxxxxxxxxxx wrote:
On 3/11/21 9:12 PM, Pratyush Yadav wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> Check if a read is eligible for PHY and if it is, enable PHY and DQS.
DQS as in data strobe? Shouldn't the upper layer inform the QSPI
controller
whether DS is required or not?
Yes, DQS as in data strobe. I need to check this again, but IIRC the
controller cannot run in PHY mode unless DS is used. Ideally the upper
layer should indeed inform the controller whether DS is
supported/in-use
or not. That can be used to decide whether PHY mode (and consequently
the DS line) is to be used or not.
Currently there are only two flashes that use 8D-8D-8D mode (S28HS512T
and MT35XU512ABA), and both of them drive the DS line.
The LS1028A datasheet explicitly states that the calibration is only
used for non-DQS flashes. Which makes sense, because it just determine
at
which point the input data is sampled. And if the flash provides a data
strobe, it already know when to sample it. What I am missing here?
-michael
