I am receiving an unexpected reply from the ASR-1 when the MCU sends a Zero Sync on SPI. After each interrupt from the ASR-1, the MCU clocks out the Zero Sync on MOSI (0x30 0x00 0x00 0x00 0x00 0x30) and 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa is clocked in on MISO. Can anyone explain this please?
I was expecting to see 0x30 0x00 0x00 0x00 0x00 0x30 or similar on MISO.
The SPI is setup for little endian, clock low during idle, data set on clock rising edge. Clock frequency is ~500kHz.