AnsweredAssumed Answered

Boot time

Question asked by FAE@toronto2 on Nov 8, 2016
Latest reply on Nov 25, 2016 by Hao.Liang

I have a design using a BF606 and it’s taking ~7 seconds for a 5MB boot image…


We found that the weakness seems to be the SPI driver? Increasing the SPI speed from 25MHz to 62.5MHz made no difference. From scoping we found that there is a fixed overhead of about 1us per byte no matter what the SPI speed, which means that reading a 5 MB image has a 5 second overhead no matter how fast the actual SPI reads (about 0.1us per byte at 62.5MHz). To put it another way, the SPI bus is idle 90% of the time during the ~7s load time?


The current driver does not use DMA which is probably the real problem?


Any thoughts or comments would be appreciated. Thanks!!