A method of data communication at a device coupled to a serial bus, comprising: receiving a write command from the serial bus, the write command being received in a datagram and configured in accordance with a System Power Management Interface, SPMI, protocol; writing a data byte received in a first data frame of the datagram to a register address identified by the datagram; and using a second data frame of the datagram to provide feedback regarding the datagram, including: driving a data line of the serial bus to provide a negative acknowledgement during the second data frame when a transmission error is detected in the datagram; and refraining from driving the data line of the serial bus during the second data frame when no transmission error is detected in the datagram, thereby providing an acknowledgement of the datagram, further comprising: enabling a line driver coupled to the data line of the serial bus to actively drive the data line to a high signaling state when providing the negative acknowledgement during the second data frame; characterized in further comprising: activating the line driver when a seventh pulse is detected on a clock line of the serial bus during the second data frame; and driving the data line of the serial bus to the high signaling state while an eighth pulse is detected on the clock line of the serial bus during the second data frame. receiving a write command from the serial bus, the write command being received in a datagram and configured in accordance with a System Power Management Interface, SPMI, protocol; writing a data byte received in a first data frame of the datagram to a register address identified by the datagram; and using a second data frame of the datagram to provide feedback regarding the datagram, including: driving a data line of the serial bus to provide a negative acknowledgement during the second data frame when a transmission error is detected in the datagram; and refraining from driving the data line of the serial bus during the second data frame when no transmission error is detected in the datagram, thereby providing an acknowledgement of the datagram, further comprising: enabling a line driver coupled to the data line of the serial bus to actively drive the data line to a high signaling state when providing the negative acknowledgement during the second data frame; characterized in further comprising: activating the line driver when a seventh pulse is detected on a clock line of the serial bus during the second data frame; and driving the data line of the serial bus to the high signaling state while an eighth pulse is detected on the clock line of the serial bus during the second data frame. driving a data line of the serial bus to provide a negative acknowledgement during the second data frame when a transmission error is detected in the datagram; and refraining from driving the data line of the serial bus during the second data frame when no transmission error is detected in the datagram, thereby providing an acknowledgement of the datagram, further comprising: enabling a line driver coupled to the data line of the serial bus to actively drive the data line to a high signaling state when providing the negative acknowledgement during the second data frame; characterized in further comprising: activating the line driver when a seventh pulse is detected on a clock line of the serial bus during the second data frame; and driving the data line of the serial bus to the high signaling state while an eighth pulse is detected on the clock line of the serial bus during the second data frame. enabling a line driver coupled to the data line of the serial bus to actively drive the data line to a high signaling state when providing the negative acknowledgement during the second data frame; characterized in further comprising: activating the line driver when a seventh pulse is detected on a clock line of the serial bus during the second data frame; and driving the data line of the serial bus to the high signaling state while an eighth pulse is detected on the clock line of the serial bus during the second data frame. activating the line driver when a seventh pulse is detected on a clock line of the serial bus during the second data frame; and driving the data line of the serial bus to the high signaling state while an eighth pulse is detected on the clock line of the serial bus during the second data frame.