On 12/03/21 11:20AM, Michael Walle wrote: > Am 2021-03-12 11:10, schrieb Pratyush Yadav: > > There is usually a delay from when the flash drives the data line (IOW, > > puts a data bit on it) and when the signal reaches the controller. This > > delay can vary by the flash, board, silicon characteristics, > > temperature, etc. > > Temperature might change over time, but the calibration is only done > once. I don't know how much influence the temperature actually has, but > our boards are usually operating from -40°C to +85°C. So there might be > a possible temperature difference of 125K between actual calibration and > when the flash is accessed. The algorithm supports a temperature range of -45 C to +130 C. The temperature is checked at calibration time and adjustments are made to make sure the reads work over the entire temperature range [0]. [0] The current implementation does not have a way to query the temperature from the sensor (see cqspi_get_temp()), so it always assumes the temperature at calibration time is 45 C. But that can be added later once the temperature sensor driver is implemented. -- Regards, Pratyush Yadav Texas Instruments Inc.
