I'm trying to use a MC9S08DZ128MLL
but i still dont undestand the clock part
let's make this a hardware approach
the internal reference clock can only provide 25 kHz to 41.66 kHz
1) but i need a real time clock here, so i need a 32kHz crystal attached... to both XTAL and EXTAL, right?
but what if i want a faster clock sometime?
2)lets say i'd want to work at 16MHz someday using the same hardware. is there a way to have both the 32kHz and the 16MHz crystals available to select? or would i have to remove one and place the other manually?
now, this is a software question
3) how do i make the micro work at 40MHz?
in hardware i understand i need to attach a square wave input clock en EXTAL, leaving XTAL free
what would be a good choice for the clk?
and how should i configure the micro to work with this?