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Flash memory interfacing LPC1788 does not exit busy state

Question asked by Eric Kim on Oct 9, 2017
Latest reply on Oct 19, 2017 by Carlos_Mendoza

Hi

 

I am working on a project using LPC1788 micro-controller. I should mention that this micro has external memory controller and the micro interfacing flash using its own controller.

I'm trying to make an external flash memory work, but the problem is after erasing one block, the flash does not exit from the busy state. I use an oscilloscope to see the R/B signal and it never returns to its ready state. I have provided some time after the erase operation to create enough time for flash, but it does not work.

I initialized the memory controller's timing registers but I am not definitely sure whether they are correct.

Another issue which may contribute to this problem is that, for every command or every address i provide, my chip select signal changes its state. What I mean is that for every command/address it becomes low and then returns to high. But the diagram in the flash datasheet shows that it should becomes active, just once for the whole operation.

 

every suggestion would be greatly appreciated,

Eric

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