I'm trying to replace my AT91SAM7S256 with SAM3S8B micro controller which is sitting on my board. I feel like when I connect my board to USB port and use HID class, my SAM3 micro becomes a bit hotter than SAM7 micro. But I'm not sure that it is normal or abnormal.
"for otherwise identical CMOS devices running at the same speed the slower device (slower rise/fall times) will get a bit warmer"
That's why when you cut clock to any CMOS devices, they burn up instantaneously.
Only in the malund universe, :)
someone can't read
rise/fall times are independent of clock speed
But you understand that CMOS devices are "static" devices?
They draw almost zero power in a static state - their energy loss (and heat generation) comes from the transitions.
More modern chips have faster transitions with less capacitances to charge/discharge. So a more modern chip can run at the same clock frequency with a lower loss.
So it is an power advantage to get a more recent chip capable of 120 MHz and run it at 60 MHz instead of getting an earlier release that maxes out at 60 MHz and have it run flat out.
Or are you disagreeing? Oops - you did.