03-20-2008 10:11 AM
We're developing a firmware for a prototype datalogger. Our data is about 140KB/s. Most of the cards we tested, including SanDisk standard SD cards (not ultra,extreme series) would work fine if we have more data buffers. What we're seeing in our SanDisk 1GB cards is that the busy signal after writing a 512 bytes block takes most of the times 2ms. However there are spikes of 240ms for the busy that makes our little 10k buffer overflow. It seems that those spikes happen on 128KB intervals.
So the huge question here is. What's the maximum busy spike time for the extreme III and ultra II SanDisk SD cards?