This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TRF7970A does not respond to IRQ register read

Other Parts Discussed in Thread: TRF7970A, TRF7960A

Hello

I have been working with a TRF7970A and Freescale MX27 MCU. The two are connected via SPI with SS. I can read the TRF's registers, and modify them.

My problem comes when I receive the first IRQ after the inventory command and send the "read IRQ register" (0x6C, followed by two 0x00 bytes). the chip does not respond all the time to the IRQ read, and it does not reset it. However, sometime the chip does respond (0xA0), even if nothing changes in the code, and I can see the interrupt pin reset and the second interrupt.

My inventory command has the format: 0x8F, 0x91, 0x3D, 0x00, 0x30, 0x26, 0x01, 0x00.

Is it a timing issue here? Do I have to do a reset command after the inventory?

Help is greatly appreciated.

Best regards,

Andrei