CPMUAPITR on s12p

sprince — Tue, 27 Oct 2009 03:21:25 GMT

I'm trying to determine if it is possible to use the internal clock on the s12p. How accurate is the internal clock on the s12p when trimmed at the factory using CPMUAPITR?

I guess one would have to know what the tolerance is on a typical oscillator. If an oscillator has a frequency of 4Mhz and a tolerance of 100ppm, does this mean 4Mhz+/- .01%? If so, the internal oscillator would have to be trimmed extremely well to be similar. If it is similar to s08 products, the accuracy is around +/-5%. Not good enough for my application (need .5%).

thanks in advance

Re: CPMUAPITR on s12p

Fast — Sun, 08 Nov 2009 21:31:25 GMT

Why not add the external crystal, I think this is cheaper than testing every unit at say 0 and +50degC to calibrate both internal die temperature and internal oscillator, but +/-1.5% is good enough except perhaps for 1Mbit/sec CAN.

The cost and toughness advantage of no crystal are attractive especially in hostile environments where this part excels. Like all engineering you must balance price and performance.

Fast55

topic CPMUAPITR on s12p in S12 / MagniV Microcontrollers

CPMUAPITR on s12p

Re: CPMUAPITR on s12p