I modified the program to log three ADC channels every 1024 microseconds.
I added another performance measure, the minimum number of free data records. For the the three ADC test the result is:
Done
Maximum SD write latency: 48364 usec
Minimum free record count: 89
Unused Stack: 57 152
I ran for about 15 minutes with a high quality industrial SD. I allocated 150 FIFO records and the minimum number of free records was 89 so I was never close to an overrun.
The log file size was about 10 MB.
pito,
Thanks for your effort to find the compiler bit field bug. Compiler bugs can be nasty.