I have developed an own PCB design based on Denebola development kit. Whit the following differences:
- the SPI FLASH, which is used to store the firmware image, is supplied by 1.8V. Because I have replaced the 3.3V domain by 1.8 V.
- The boot mode is fixed to start always as SPI mode. But I can also start in USB boot mode in order to update the firmware embedded in SPI FLASH memory.
My own design works correctly if I supply the firmware through USB boot mode, I mean, in this case, I program the CX3 through RAM using the USB Control Center, embedded in the Cypress EZ USB Suite.
But I have detected an issue, also in my own design, When I try to supply the firmware from the SPI FLASH. Because I can store the firmware in the SPI Flash and the USB Control Center does not show me any warning.
The error appear when the CX3 has to get the firmware from the SPI FLASH, since he can't do it.
For this reason I have compared, in both Denebola and own design, the writing and reading of the firmware image between the CX3 and SPI FLASH. To do this, I have used an oscilloscope and a logic analyzer in order to be sure of the results.
I have attached the results, and as you can see. The writing process of the firmware image is exactly the same in both denebola and own design. I mean, I have registered the same writing values in the SPI FLASH.
But in the reading process from the SPI FLASH, my own design does not send the same values. Because I detect some corrupt values in dataframe.
So my question is the next:
It is possible that the memory problem is preceded by the high reflow temperature in the soldering process?.
The memory Cypress model S25FS064S, so, could you tell me please the maximum solder temperature of the device, because it is not appear in the datasheet?.