Patent ID: 8060790

Claim:
A semiconductor integrated circuit comprising: a processing unit that performs arithmetic processing according to a predetermined program and outputs trace information with respect to the arithmetic processing; and a trace compression unit that compresses the trace information outputted from the processing unit, wherein the trace compression unit comprises a storage device that stores the trace information outputted from the processing unit; a comparator unit that compares trace information stored in the storage device with the trace information newly outputted from the processing unit and outputs a comparison result; and a trace information compression controller that compresses trace information to be externally outputted, based on the comparison result of the comparator unit, wherein, when the newly-outputted trace information from the processing unit is in disagreement with the trace information stored in the storage device, the trace information compression controller stores the newly-outputted trace information into the storage device after appending an index number to the newly-outputted trace information, and wherein, when the newly-outputted trace information from the processing unit is in agreement with the trace information stored in the storage device, the trace information compression controller compresses the trace information to be externally outputted by replacing the trace information to be externally outputted with an index number appended to the trace information concerned in the storage device.