SPI Interrupt

[lpcware]

Content originally posted in LPCWare by Philipp on Fri Nov 12 04:24:50 MST 2010
Hi
I have a problem with the SPI Interrupt. I enabled the RTIM Interrupt. I get this interrupt after the second data frame and after a periode of 125us. The Time depends on the Frequency. Is there an other solution of getting an Interrupt without asking the RNE status Bit permanently?
And is it correct that the Interrupt triggers after the second Data? Is there an Option to set this variable.
Thanks for Help

[lpcware]

Content originally posted in LPCWare by Philipp on Mon Nov 15 04:12:00 MST 2010
Okay I found the Problem. The Time between Command 1 and 2 was too short. The second fault, the Time till the Interrupt was too high because my Registers were badly set. My SPICLOCKDIV was 2, I set it now on 1. That's a faktor of 2.
To reduce the time, I set the CLOCK PRESCALE REGISTER on a higher number. With CPR of 6 now, I have an Interrupt Time of  5us.

Can anyone explain me, how this number compose? Is there a Formula?
Thanks for help