I have some stepper motor control code that I'm porting over from a PIC that uses an 8 usec (micro-seconds) timer (TMR4). To keep the control the same, I need to generate an 8 usec timer interrupt on the LPC804. My target is an LPC804_TSSOP20 which is Part Number LPC804M101JDH20 but I have an LPCXpresso804 Rev B OM40001 board to do testing with.
I was looking at using a CTimer or an MRT timer to generate this 8 usec interrupt and I found an MRT example here on the forum from @jeremyzhou
To test, I'm using the identical code from this posting on my LPCXpresso804 Rev B OM40001 board:
https://community.nxp.com/t5/LPC-Microcontrollers/LPC804-maximum-MRT-frequency/m-p/992300/highlight/...
But instead of seeing a frequency of 125.7 kHZ and a period of 7.956 us, I'm seeing a frequency of 44.7 kHz and a period of 22.35 us. Any ideas why?
Scope of the MRT timer firing the LED
What would be the best way for me to generate the 8 usec timer interrupt that I need?