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STM32 DMA Limitation ?

Question asked by patel.vishal.006 on Mar 8, 2017
Latest reply on Mar 9, 2017 by patel.vishal.006

Application Scenario: We have used DMA, FSMC, and DCMI module of the  STM32. DMA is configured
to read the data from the DCMI out output  register DR, and write it it to external SRAM. Likely DCMI is
configured  as an Peripheral and SRAM is configured as a memory port of the DMA.  Data transfer width
is configured as an word in case of peripheral port  and half-word in case of memory port. SRAM is configured
on address  0x64000000.  Problem: The whole system works fine as long as we configure DCMI to take JPEG

image up to 262KByte, but when we configured it to take picture of the higher  quality, DMA is not able to store

the data in SRAM, above the address  3ffff, so we get only 262143 bytes maximum. after that we receive only 0xFF. 

What we have verified so far: 1) FSMC part is configured fine 2) SRAM is  written and read back by using internal memory, it works fine. 3) I  believe there is no point of having doubts on DCMI module, If It is not  configured good then It should not be working for the images under 262K.

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