Hello Gilbert,
Please provide more details about your setup (HW and SW):
- Are you measuring the voltages and oscillation in the evaluation board or in a custom board with the PN7150?
- Have you verified that the I2C communication is working and the PN7150 responds to the KL17?
- What software are you using, the example NXP-NCI project?
About CLOCK_SEL_CFG, your understanding is incorrect. Pay attention to the bit position:
Default value is 0x11 = 0b00010001.
- Bits [4:3] are for Clk Source. Default value is 10b = PLL.
- Bits [2:0] are for Clk In frequency. Default value is 001 = 19.2 MHz.
To configure for a 27.12 MHz crystal you can use for example the value 0x08 = 0b00001000 (bits [4:3] = 01).
The command frame to send for this configuration would be [0x20 0x02 0x05 0x01 0xA0 0x03 0x01 0x08].
Best Regards!
Jorge Gonzalez