An embedded controller includes a central processing unit, a memory interface
for interface with an external memory, and a function block or peripheral device
with a register for storing operation state information. The peripheral device
includes a detection circuit, a storage unit, for example in the form of a FIFO,
a multiplexer, and a direct memory access (DMA) controller. The state detection
circuit activates a flag signal whenever the operation state information of the
register is varied, and the FIFO stores the operation state information from the
register in response to the flag signal. The multiplexer is controlled by the DMA
controller and transmits the operation state information of the FIFO to an internal
bus. As a result, the operation state information of the FIFO is stored in the
external memory through the memory interface.