I am using the ADuC845 micro connected via SPI to a MAX3109 dual uart device. This interface is working well. I also want to use the ADuC845's I2C interface (configured in hardware slave mode) for communications with another processor on my board. I read that both the SPI and I2C functionality can be used simultaneously with the ADuC845 micro. However on page 63 of the user manual it mentions that it is necessary to clear the SPE bit in the SPICON register in order to enable the I2C hardware slave functionality on the part. However on page 65 it mentions that the SPE bit shout be set to enable the SPI interface. So I am a confused as to exactly how to enable both SPI along with I2C hardware slave functionality on the part simultaneously.