48Mhz isn't always such a good thing unless you'll be using USB.Originally Posted by comwarrior
With almost any other 18F device you can run at 40Mhz.
That extra 8Mhz doesn't really add much speed, but it really messes up the math when trying to do things.
Instead of the nice round 0.1uS instruction cycle, it's now 0.083333... repeating.
Then integer truncation causes small errors in just about everything you try to calculate against time.
If you will be using USB, then it's just something you have to live with, unless you run the CPU at a different speed while still giving 48Mhz to the USB.
Plus one bad thing about the 18F4550 is that you can't use both the USART and the MSSP module because the the RX and SDO share the same pin. SDO was moved from RC5 to make room for the USB D+ pin.
If there's no USB ... the 18F4420/4520 is a great alternative to the 877A.
Completely pin compatible, with lots of extras.
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