Patent ID: 7047443

Claim:
A microcomputer having an on-chip debugging function, comprising: a central processing unit for executing instructions; and a first monitor section that performs data transfer to and from a second monitor section, determines a primitive command to be executed based on the data received from the second monitor section, and performs processing for execution of the determined primitive command, the second monitor -section being provided outside the microcomputer and -performing a processing to convert a debugging command into at least one primitive command; a receive buffer that temporarily stores the data received from the second monitor section; and a send buffer that temporarily stores send data to the second monitor section, wherein the data received from the second monitor section includes identification data that identifies a primitive command, wherein the first monitor section obtains a read address from the received data in the receive buffer, reads data from the obtained read address and writes the read data to the send buffer, when the identification data included in the received data represents a primitive command of a read command, and wherein the first monitor section obtains a write address and write data from the received data in the receive buffer, and performs a processing to write the obtained write data to the obtained write address, when the identification data included in the received data represents a primitive command of a write command.