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Kinetis MKW22D512 minimal boot environment problems

Question asked by Jonathan Bartowski on Jul 10, 2015
Latest reply on Jul 13, 2015 by David E Seymour

Hello. I am trying to program a MKW22D512 on a custom PCB, but I haven't been able to get my JLink JTAG/SWD programmer to recognize the chip on my third PCB. I've wired VDDA, VDD_MCU, VBAT_MCU on the same rail to a 3.3v supply (i.e., pins 38, 32, 25, and 20 are all on a common wire), and the EzPort chip select (pin 36) is pulled high because I'm using a JTAG/SWD programmer. The ground pads and VSSA (pin 28) are both connected to a ground, and the RESET_b pin (pin 41) is connected to ground because it's active low. I've tried connecting and disconnecting the Pierce crystal oscillator circuit (pins 1 and 56) to see if it changed anything, but both times I read a 32 kHz waveform from CLK_OUT. I'm fairly confident that there isn't a fabrication or assembly issue, but when I connect my JLink with the latest software from Segger there are no interfaces found. Is there anything obvious that I'm doing improperly or haven't done to setup the chip for JTAG/SWD programming? Thank you very much for any insight you can offer.