FAT component timing
Posted: Fri Dec 22, 2017 12:42 pm
Hello all
I have noticed on my hardware that changing the SD card HighSpeed Pre-scale value has little effect on the time it takes the thing to execute. Measurements that I have obtained are Fosc/4 : 305mS, Fosc/16 : 304mS, Fosc/64 : 306mS. My Oscillator is running at 32MHz and the string I am sending is about 70 characters. In all three observations the string is correctly recorded.
I have the Initial Pre-scale value at Fosc/64 and, at that initialisation time, have the oscillator running at 8MHz. I have not measured this timing.
Any ideas why the period is not changing for different clock speeds?
Regards
Howard
FC 7.2.1.4 PIC18F46K22
I have noticed on my hardware that changing the SD card HighSpeed Pre-scale value has little effect on the time it takes the thing to execute. Measurements that I have obtained are Fosc/4 : 305mS, Fosc/16 : 304mS, Fosc/64 : 306mS. My Oscillator is running at 32MHz and the string I am sending is about 70 characters. In all three observations the string is correctly recorded.
I have the Initial Pre-scale value at Fosc/64 and, at that initialisation time, have the oscillator running at 8MHz. I have not measured this timing.
Any ideas why the period is not changing for different clock speeds?
Regards
Howard
FC 7.2.1.4 PIC18F46K22