I cannot enable the SPI MISO line on my ADuC7026. The SPI is configured in slave mode. Using an oscilloscope, I see ~CS go low and the master start clocking SCLK. I can successfully receive bytes on MOSI. However, it appears that MISO is permanently stuck in high-impedance mode. I've tried many combinations of settings in the SPICON register, but nothing happens on MISO. Any suggestions?