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STM32F437 External Memory Interface

Question asked by PeterT on Apr 13, 2015

In one of our embedded systems we use a MR256A08B MRAM in conjunction with a STM32F437 microcontroller. Sometimes (increasing with temperature) we are observing the problem that we cannot write to discrete bits of the MRAM.

We assume a timing issue.

 

The datasheet of the MRAM specifies a write recovery time tWHAX (address hold time after write high) of at least 12 ns. The controller gives us only 6 ns (tHCLK + 0.5 ns), with the current timing settings.

 

Is there a chance to extend the 6 ns without cutting the HCLK-frequency from 180 MHz down to maybe 80 MHz?

Could the BusTurnAround parameter do this job? Unfortunately the datasheet does not clearly show what is happening during the bus turn around time.

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