I wired up an ATmega128RFA1 according to the application circuit in the datasheet (page 493). Everything worked fine until I set the SUT_CKSEL fuse to:
Tranceiver Oscillator: Start-up time: 16 CK + ms
. . . then it stopped responding . . .
Lowering the ISP frequency to any speed doesn't help.
CKDIV8 and CKOUT are unchecked, and I haven't programmed the device yet.
I have a 16MHz crystal (mouser #815-ABM10-16-E20-T) with two 10pF caps (mouser says its a 20pF crystal, but the crystal datasheet says use 10pF). If I've read page 494 of the manual correctly, then the 16MHz crystal is the transceiver crystal.
note: The trace length between both ends of the crystal to the ATmega aren't equal on my board. One is 30% (0.09 inches) longer . . . could that break it?
What am I doing wrong?