SNIU028D February 2016 – September 2020 UCD3138 , UCD3138064 , UCD3138064A , UCD3138128 , UCD3138A , UCD3138A64
Quick commands are initiated in Master Mode by simply programming the desired slave device address into the Master Control Register. The byte count within the Master Control Register is configured to 0 bytes by writing all zeros to bits 15-8. Upon transmission of the device address, the PMBus Interface will monitor the slave acknowledgement of the address. If the address is not acknowledged, the Nacked bit within the status register is enabled and the PMBus Interface automatically enables a stop condition on the PMBus to terminate the message. If the address is acknowledged, a data request is issued to the processor. The firmware writes a ‘0’ to the Acknowledge Register to terminate the message, forcing the PMBus Interface to write a stop condition onto the PMBus.