Eugene, >> what is the resolution of gettimeofday() for an MPC8xx? >> >> IIUC then the "decrementer" is used to generate the timer interrupts every >> 10ms. >> >> This decrementer runs at cpuclk/16. Thus with 80MHz CPU clock has a >> resolution of 16/80MHz = 200ns and overflows every 50000 ticks. >> >> But is this decrementer used to update xtime? >> Will gettimeofday() have a resolution of 200ns? >> >> How about linux 2.4 where xtime is a "struct timeval" rather then "struct >> timespec"? >> > > Usually on PPC we use timebase to interpolate time between Decrementer > interrupts. In this case gettimeofday resolution is determined by > timebase resolution which is quite high (megahertz range).
Sorry. I don't understand. What do you mean with "timebase"? Is there a second timer/counter? -- Steven
