Abstract: Disclosed is an IC firmware update method performed by an intermediary circuit. The method includes: communicating with a target circuit to enter a predetermined mode; transmitting a status response message to a host circuit in response to a status asking message of the host circuit so as to inform the host circuit of its entrance to the predetermined mode; after the transmission of the status response message, receiving a first protocol request command of the host circuit; converting the first protocol request command into N request-end unstructured vendor defined message(s) (USVDM(s)) and transmitting the N request-end USVDM(s) to the target circuit to let it execute a firmware update operation, in which the N is a positive integer; receiving N response-end USVDM(s) of the target circuit related to the N request-end USVDM(s); and converting the N response-end USVDM(s) into a first protocol response command and transmitting it to the host circuit.

Abstract: Disclosed is an IC firmware update method performed by an intermediary circuit. The method includes: communicating with a target circuit to enter a predetermined mode; transmitting a status response message to a host circuit in response to a status asking message of the host circuit so as to inform the host circuit of its entrance to the predetermined mode; after the transmission of the status response message, receiving a first protocol request command of the host circuit; converting the first protocol request command into N request-end unstructured vendor defined message(s) (USVDM(s)) and transmitting the N request-end USVDM(s) to the target circuit to let it execute a firmware update operation, in which the N is a positive integer; receiving N response-end USVDM(s) of the target circuit related to the N request-end USVDM(s); and converting the N response-end USVDM(s) into a first protocol response command and transmitting it to the host circuit.