Semiconductor device

Abstract

A semiconductor device in which the area of a circuit that is unnecessary during normal operation is small. The semiconductor device includes a first circuit and a second circuit. The first circuit includes a third circuit storing at least one pair of first data including a history of a branch instruction and a first address corresponding to the branch instruction; a fourth circuit comparing a second address of an instruction and the first address; and a fifth circuit selecting the first data of one pair among the at least one pair in accordance with a comparison result. The second circuit includes a plurality of sixth circuits having a function of generating a signal for testing operation of the first circuit in accordance with second data, and a function of storing the at least one pair together with the second circuit after the operation is tested.

What is claimed is: 
     
         1 . (canceled) 
     
     
         2 . An electronic device comprising:
 a first circuit comprising a first memory; and   a second circuit comprising a second memory and a logic array,   wherein the first memory is configured to store first data corresponding to a history of a first branch instruction of the first circuit,   wherein the second memory is configured to store second data for controlling electrical continuity between circuits in the logic array and an output signal with respect to an input signal of the circuits in the logic array to generate a signal for testing an operating state of the first circuit in a test for the operating state of the first circuit, and third data corresponding to a history of a second branch instruction of the first circuit in normal operation after the test, and   wherein the electronic device is at least one of a display device, a personal computer, an image reproducing device, a mobile phone, game machine, a portable information appliance, an e-book reader, a video camera, a digital still camera, a goggle-type display, a head mounted display, an navigation system, an audio reproducing device, a copier, a facsimile, a printer, a multifunction printer, an automated teller machines, a vending machines, and a medical equipment.   
     
     
         3 . The electronic device according to  claim 2 ,
 wherein the second memory comprises a first transistor and a second transistor, and   wherein a first terminal of the first transistor is electrically connected to a gate of the second transistor.   
     
     
         4 . The electronic device according to  claim 3 ,
 wherein an on/off state of the second transistor is selected according to the second data input through the first transistor.   
     
     
         5 . The electronic device according to  claim 3 ,
 wherein the first transistor comprises a channel formation region comprising an oxide semiconductor.   
     
     
         6 . The electronic device according to  claim 5 ,
 wherein the oxide semiconductor comprises at least one of In, Ga, and Zn.   
     
     
         7 . An electronic device comprising:
 a first circuit comprising a first memory and a comparator circuit; and   a second circuit comprising a second memory and a logic array,   wherein the first memory is configured to store first data corresponding to a history of a first branch instruction of the first circuit and a first address of the first branch instruction,   wherein the comparator circuit is configured to compare an address of an instruction and the first address,   wherein the second memory is configured to store second data for controlling electrical continuity between circuits in the logic array and an output signal with respect to an input signal of the circuits in the logic array to generate a signal for testing an operating state of the first circuit in a test for the operating state of the first circuit, and third data corresponding to a history of a second branch instruction of the first circuit and a second address of the second branch instruction in normal operation after the test, and   wherein the electronic device is at least one of a display device, a personal computer, an image reproducing device, a mobile phone, game machine, a portable information appliance, an e-book reader, a video camera, a digital still camera, a goggle-type display, a head mounted display, an navigation system, an audio reproducing device, a copier, a facsimile, a printer, a multifunction printer, an automated teller machines, a vending machines, and a medical equipment.   
     
     
         8 . The electronic device according to  claim 7 ,
 wherein the second memory comprises a first transistor and a second transistor, and   wherein a first terminal of the first transistor is electrically connected to a gate of the second transistor.   
     
     
         9 . The electronic device according to  claim 8 ,
 wherein an on/off state of the second transistor is selected according to the second data input through the first transistor.   
     
     
         10 . The electronic device according to  claim 8 ,
 wherein the first transistor comprises a channel formation region comprising an oxide semiconductor.   
     
     
         11 . The electronic device according to  claim 10 ,
 wherein the oxide semiconductor comprises at least one of In, Ga, and Zn.   
     
     
         12 . The electronic device according to  claim 7 ,
 wherein the first circuit comprises a selector circuit configured to select the first address in accordance with a comparison result of the comparator circuit.   
     
     
         13 . The electronic device according to  claim 12 ,
 wherein the second memory comprises a first transistor and a second transistor, and   wherein a first terminal of the first transistor is electrically connected to a gate of the second transistor.   
     
     
         14 . The electronic device according to  claim 13 ,
 wherein an on/off state of the second transistor is selected according to the second data input through the first transistor.   
     
     
         15 . The electronic device according to  claim 13 ,
 wherein the first transistor comprises a channel formation region comprising an oxide semiconductor.   
     
     
         16 . The electronic device according to  claim 15 ,
 wherein the oxide semiconductor comprises at least one of In, Ga, and Zn.   
     
     
         17 . An electronic device comprising:
 a processor comprising a branch prediction circuit; and   a programmable logic device,   wherein the programmable logic device is a first configuration of a test circuit for testing an operating state of the processor in a test for the operating state of the processor and a second configuration of an additional part of the branch prediction circuit in a normal operation after the test, and   wherein the electronic device is at least one of a display device, a personal computer, an image reproducing device, a mobile phone, game machine, a portable information appliance, an e-book reader, a video camera, a digital still camera, a goggle-type display, a head mounted display, an navigation system, an audio reproducing device, a copier, a facsimile, a printer, a multifunction printer, an automated teller machines, a vending machines, and a medical equipment.   
     
     
         18 . The electronic device according to  claim 17 ,
 wherein the programmable logic device comprises a memory comprising a first transistor and a second transistor, and   wherein a first terminal of the first transistor is electrically connected to a gate of the second transistor.   
     
     
         19 . The electronic device according to  claim 18 ,
 wherein the first transistor comprises a channel formation region comprising an oxide semiconductor.   
     
     
         20 . The electronic device according to  claim 19 ,
 wherein the oxide semiconductor comprises at least one of In, Ga, and Zn.