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Discussion - EVE / FT812 Quad SPI interface
« on: March 12, 2021, 09:54:30 AM »
I have a NXP uC connected by quad SPI to the FT812 chip. When running at full speed in quad mode I get problems with reading data from the Ft chip.
The first 2 bytes read back after sending address is just repetition of last 4bits of the address. I've tried different drive strengths(both command wise and GPIOX reg) settings and dummy byte settings without success.
(That's also an interesting thing where it in sample code for the FT81x is used two dummy bytes in quad mode without explanation in data sheet or program manual. Why is that?)
At lower speed, aprox 16MHz I get correct output data, at speeds in between it is a mix of faulty and correct readings. Is there any known explanation to this or ways to handle it?
Is there any errata sheet for the FT812?
Best Regards
Goran
The first 2 bytes read back after sending address is just repetition of last 4bits of the address. I've tried different drive strengths(both command wise and GPIOX reg) settings and dummy byte settings without success.
(That's also an interesting thing where it in sample code for the FT81x is used two dummy bytes in quad mode without explanation in data sheet or program manual. Why is that?)
At lower speed, aprox 16MHz I get correct output data, at speeds in between it is a mix of faulty and correct readings. Is there any known explanation to this or ways to handle it?
Is there any errata sheet for the FT812?
Best Regards
Goran