Microcomputer
AssigneesInternational Business Machines Corporation, Mitsubishi Electric System LSI Design Corporation, Mitsubishi Denki Kabushiki Kaisha
InventorsSakae Itoh, Teruaki Kanzaki, Tadayuki Akatsuki, Tatsuya Sakai, Tsutomu Numata, Yasuhiro Nakamura
Life of this patent
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Abstract
A microcomputer contains an electrically erasable flash memory for storing a program under development and a debugging circuit 7 having a dedicated input/output terminal for connection to an external ICE 14, and the debugging circuit 7 has a function of communication with a CPU 1, a function of communication with the ICE 14, a function of tracing the operating condition of the CPU 1, a break function of generating a debug interrupt, a function of writing a program code from the ICE 14 into the flash memory 6 and a function of sending the contents of the flash memory 6 to the ICE 14.
Claims4
A microcomputer which is provided with a central processing unit that operates using a program stored in a read-only memory connected thereto via an internal bus, said microcomputer comprising:
- an electrically erasable flash memory for storing an under-development version of said program which is stored in said read-only memory;
- and
- a debugging circuit connected via said internal bus to said central processing unit and having a dedicated input/output terminal for connection to an external emulator;
- wherein said debugging circuit comprises:
- a function of communication with said central processing unit via said internal bus;
- a function of communication with said emulator via said dedicated input/output terminal;
- a trace function of sending information on the operating condition of said central processing unit to said emulator via said dedicated input/output terminal;
- a break function of generating a debug dedicated interrupt when the operating condition of said central processing unit meets a condition preset by said central processing unit or said emulator;
- and a function of writing in said flash memory a program code sent from said emulator via said dedicated input/output terminal and reading out the contents of said flash memory and sending them to said emulator via said input/output terminal.
Dependencies are inferred from the claim text.