I plan to use the ATMega328 - TQFP and also the DS3234 real time clock chip that connects over SPI. I will have to break out the icsp header on my board to burn the bootloader on the atmega. Will the DS3234 interfere with this process. I'll probably just burn the bootloader before mounting the DS3234, but I'd still like to know the answer to this...
Not usually, since the cs of a device tells it to have high impedance lines so that you can do just that
While the processor is being programmed ensure the DS3234 slave select is not asserted (not low).
If the DS3234 has a /RESET, tying the two /RESETs together may also work.
Any results? What worked? I'm trying to do the same.
Put an external pullup resistor on the pin you use for Ds3234 cs so it remains inactive while ICSP is in use and Reset is asserted.