US 5,940,783 AGranted

Microprocessor and method of testing the same

AssigneeMatsushita Electric Industrial Co., Ltd.

InventorsAtsushi Kukutsu, Kozo Nuriya, Takao Ohkawara, Junji Soga, Tadashi Yoshino

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Abstract

A microprocessor includes an assign function for assigning ports to a mode identifying unit, test signal input unit, and test result signal output unit, a test implement function for sending test results to the test result signal output unit according to the test data signals input from the test signal input unit, and an activation control function for activating the test implement function upon identifying a test mode by the status of the mode identifying unit. When a test mode signal from test equipment is received at the test mode identifying unit assigned to one port of the microprocessor, the test signal input unit and the test result signal output unit are assigned to other ports of the microprocessor, and when the test data signals from the test equipment are received at the test data signal input unit, test result signals according the test data signals are output from the test result signal output unit.

Claims15

Dependent claims

A test method for testing electrical connections between a circuit board and ports of a microprocessor mounted on said circuit board, said method involving the use of test equipment which transfers signals to and from said microprocessor, said microprocessor including a storage means storing an assign function for assigning one port of said microprocessor to mode identifying means for identifying a test mode and other ports of said microprocessor to test signal input means and test signal output means, respectively, in accordance with inputoutput directions of said other ports of said microprocessor;

a test implement function for causing said test signal output means to output a test result signal corresponding to a test data signal supplied from said test signal input means;
and an activation control function for detecting that said mode identifying means is in said test mode and then invoking said assign function and activating said test implement function, said method comprising:
(a) employing said test equipment to apply a test mode signal to said test mode identifying means;
(b) turning on power to said microprocessor;
(c) thereafter employing said microprocessor to perform initialization and then to invoke said assign function to assign said one port of said microprocessor to said test mode identifying means;
(d) employing said microprocessor to invoke said activation control function to (i) determine that said mode identifying means is in said test mode, (ii) thereafter to invoke said assign function to assign said other ports of said microprocessor to said test signal input means and said test signal output means in accordance with said input/output directions of said other ports of said microprocessor, and (iii) to activate said test implement function;
(e) employing said test equipment to apply said test data signal to said test signal input means;
(f) employing said microprocessor to invoke said test implement function to cause said test signal output means to output said test result signal corresponding to said test data signal;
and
(g) employing said test equipment to capture said test result signal and judge test results in accordance with said test result signals, thereby accomplishing the testing of said connections.

7 more elements

A test method for testing electrical connections between a circuit board and ports of a microprocessor mounted on said circuit board, said method involving the use of test equipment which transfers signals to and from said microprocessor, said microprocessor including a storage means storing an assign function for assigning one port of said microprocessor to mode identifying means for identifying a test mode and other ports of said microprocessor to test signal input means and test signal output means, respectively, in accordance with input/output directions of said other ports of said microprocessor;

a test implement function for causing said test signal output means to output a test result signal corresponding to a test data signal supplied from said test signal input means;
and an activation control function for detecting that said mode identifying means is in said test mode and then invoking said assign function and activating said test implement function, and said method comprising:
(a) turning on power to said microprocessor;
(b) thereafter employing said microprocessor to perform initialization and then to invoke said assign function to assign said one port of said microprocessor to said test mode identifying means;
(c) employing said microprocessor to perform said activation control function in continuous fashion along with normal operation;
(d) employing said test equipment to apply a test mode signal to said test mode identifying means at the time of initiating said testing of electrical connections;
(e) employing said microprocessor to invoke said activation control function to (i) determine that said mode identifying means is in said test mode, (ii) thereafter to invoke said assign function to assign said other ports of said microprocessor to said test signal input means and said test signal output means in accordance with said input/output directions of said other ports of said microprocessor, and (iii) to activate said test implement function;
(f) employing said test equipment to apply said test data signal to said test signal input means;
(g) employing said microprocessor to invoke said test implement function to cause said test signal output means to output said test result signal corresponding to said test data signal;
and
(h) employing said test equipment to capture said test result signal and judge test results in accordance with said test result signal, thereby accomplishing the testing of said connections.

8 more elements

A test method for testing electrical connections between a circuit board and ports of a microprocessor mounted on said circuit board, said method involving the use of test equipment which transfers signals to and from said microprocessor, said microprocessor being connected to an IEEE standard 1149.1 compliant device, said microprocessor including a storage means storing an assign function for assigning one port of said microprocessor to mode identifying means for identifying a test mode and other ports of said microprocessor to test signal input means and test signal output means, respectively, in accordance with input/output directions of said other ports of said microprocessor;

a test implement function for causing said test signal output means to output a test result signal corresponding to a test data signal supplied from said test signal input means;
and an activation control function for detecting that said mode identifying means is in said test mode and then invoking said assign function and activating said test implement function, said method comprising:
(a) employing said test equipment to apply a test mode signal to said test mode identifying means;
(b) turning on power to said microprocessor;
(c) thereafter employing said microprocessor to perform initialization and then to invoke said assign function to assign said one port of said microprocessor to said test mode identifying means;
(d) employing said microprocessor to invoke said activation control function to (i) determine that said mode identifying means is in said test mode, (ii) thereafter to invoke said assign function to assign said other ports of said microprocessor to said test signal input means and said test signal output means in accordance with said input/output directions of said other ports of said microprocessor, and (iii) to activate said test implement function;
(e) employing said test equipment to send a test signal to said IEEE standard 1149.1 compliant device and thereby cause said IEEE standard 1149.1 compliant device to output said test data signal to said test signal input means of said microprocessor;
(f) employing said microprocessor to invoke said test implement function to cause said test signal output means to output said test result signal corresponding to said test data signal;
(g) employing said IEEE standard 1149.1 compliant device to capture said test result signal via an input pin and send the same to said test equipment;
and
(h) employing said test equipment to judge test results in accordance with said test result signals, thereby accomplishing the testing of said connections.

8 more elements

A test method for testing electrical connections between a circuit board and ports of a microprocessor mounted on said circuit board, said method involving the use of test equipment which transfers signals to and from said microprocessor, said microprocessor being connected to an IEEE standard 1149.1 compliant device, said microprocessor including a storage means storing an assign function for assigning one port of said microprocessor to mode identifying means for identifying a test mode and other ports of said microprocessor to test signal input means and test signal output means, respectively, in accordance with input/output directions of said other ports of said microprocessor;

a test implement function for causing said test signal output means to output a test result signal corresponding to a test data signal supplied from said test signal input means;
and an activation control function for detecting that said mode identifying means is in said test mode and then invoking said assign function and activating said test implement function, and said method comprising:
(a) turning on power to said microprocessor;
(b) thereafter employing said microprocessor to perform initialization and then to invoke said assign function to assign said one port of said microprocessor to said test mode identifying means;
(c) employing said microprocessor to perform said activation control function in continuous fashion along with normal operation;
(d) employing said test equipment to apply a test mode signal to said test mode identifying means at the time of initiating said testing of electrical connections;
(e) employing said microprocessor to invoke said activation control function to (i) determine that said mode identifying means is in said test mode, (ii) thereafter to invoke said assign function to assign said other ports of said microprocessor to said test signal input means and said test signal output means in accordance with said input/output directions of said other ports of said microprocessor, and(iii) to activate said test implement function;
(f) employing said test equipment to send a test signal to said IEEE standard 1149.1 compliant device and thereby cause said IEEE standard 1149.1 compliant device to output said test data signal to said test signal input means of said microprocessor;
(g) employing said microprocessor to invoke said test implement function to cause said test signal output means to output said test result signal corresponding to said test data signal;
(h) employing said IEEE standard 1149.1 compliant device to capture said test result signal via an input pin and send the same to said test equipment;
and
(i) employing said test equipment to judge test results in accordance with said test results signals, thereby accomplishing the testing of said connections.

9 more elements

Dependencies are inferred from the claim text.