Integrated circuit device and test method therefor
First Claim
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1. An integrated circuit device, operable in a normal mode and a test mode, the device being testable in association with a tester, including:
- an oscillator arranged to produce a periodic output signal for controlling operations of the device, during the normal mode of operation;
a counter having an input for receiving a timing signal representing operations of the device, during the normal mode of operation, and arranged to count transitions in said periodic output signal to generate an output count during the test mode of operation;
switch circuitry for selectively connecting said periodic output signal of the oscillator to the input of the counter in the test mode of operation, said test mode being implemented for a predetermined time; and
an output circuit for providing the output count generated by said counter after said predetermined time to the tester so that the tester can derive the frequency of the oscillator from said output count and said predetermined time.
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Abstract
An integrated circuit device includes an oscillator; a counter; a switch for selectively connecting the oscillator to the counter in a test mode; and an output circuit for providing the output count generated by the counter for determining the frequency of the oscillator. Thus, use is made of the normal on-chip counter in an integrated circuit to provide a reliable way of measuring the frequency of the on-chip oscillator.
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Citations
27 Claims
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1. An integrated circuit device, operable in a normal mode and a test mode, the device being testable in association with a tester, including:
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an oscillator arranged to produce a periodic output signal for controlling operations of the device, during the normal mode of operation; a counter having an input for receiving a timing signal representing operations of the device, during the normal mode of operation, and arranged to count transitions in said periodic output signal to generate an output count during the test mode of operation; switch circuitry for selectively connecting said periodic output signal of the oscillator to the input of the counter in the test mode of operation, said test mode being implemented for a predetermined time; and an output circuit for providing the output count generated by said counter after said predetermined time to the tester so that the tester can derive the frequency of the oscillator from said output count and said predetermined time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A memory device, operable in a normal mode and a test mode, the device being testable in association with a tester, including:
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an array of memory cells; decode circuitry to selectively access memory cells in said array; an oscillator arranged to produce a periodic output signal for controlling operations of the memory device during the normal mode of operation; a counter having an input for receiving a timing signal representing operations of the memory device, during the normal mode of operation, and arranged to count transitions in said periodic output signal to generate an output count during the test mode of operation; switch circuitry for selectively connecting said periodic output signal of the oscillator to the input of the counter during the test mode of operation, said test mode being implemented for a predetermined time; and an output circuit for providing the output count generated by said counter after said predetermined time to the tester so that the tester can derive the frequency of the oscillator from said output count and said predetermined time.
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14. A method of characterizing an integrated circuit device comprising the steps of:
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enabling an oscillator, provided within the integrated circuit device for controlling operations during a normal mode of operation of the device, for a predetermined time during a test mode of operation so that the oscillator produces a periodic output signal for said predetermined time; connecting said periodic output signal to the input of a counter, which is provided within said integrated circuit device for representing operations of the device in the normal mode of operation, said counter being arranged to count transitions in said periodic output signal to generate an output count during the test mode of operation; and supplying said output count to a tester capable of deriving the frequency of the oscillator from said output count and said predetermined time. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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22. An integrated circuit device, operable in a normal mode and a test mode, the device being testable in association with a tester, including:
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an oscillator arranged to produce a periodic output signal to control operations of the device during the normal mode of operation; a counter having an input for receiving, during the normal mode of operation, a timing signal representing operations of the device, and arranged to count transitions in said periodic output signal to generate an output count during the test mode of operation; switch circuitry for selectively connecting said periodic output signal of the oscillator to the input of the counter in the test mode of operation, said test mode being implemented for a predetermined time; and an output circuit for providing the output count generated by said counter after said predetermined time to the tester; and wherein the device is implemented on a single chip and the output circuit comprises at least one output pin for transmitting said output count to the tester which is off-chip.
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23. A method of testing an integrated circuit device comprising the steps of:
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enabling an oscillator, provided within the integrated circuit device for controlling operations during a normal mode of operation of the device, for a predetermined time during a test mode of operation so that the oscillator produces a periodic output signal for said predetermined time; connecting said periodic output signal to the input of a counter, which is provided within said integrated circuit device for counting operations of the device in the normal mode of operation, said counter being arranged to count transitions in said periodic signal to generate an output count during the test mode of operation; and supplying said output count to a tester capable of deriving the frequency of the oscillator from said output count and said predetermined time; and wherein the integrated circuit device is implemented on a single chip and said tester is off-chip.
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24. A method of testing an integrated circuit device, comprising steps of:
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(A) counting a number of pulses on a periodic signal generated on the device; (B) providing at least one test signal to the device from an external tester to enable the counting in step (A), the duration of the counting being determined by the at least one test signal; (C) providing the counted number to the external tester; and (D) calculating a frequency of the periodic signal in the external tester. - View Dependent Claims (25)
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26. A method of testing an integrated circuit device, the method comprising steps of:
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(A) counting a number of oscillations of an oscillating signal provided by an oscillating circuit, the oscillating signal being used by and for the operation of the integrated circuit device in a normal mode of operation, the counting occuring over a period of time; and (B) calculating a frequency of the oscillating circuit based on the number of oscillations counted and the length of the period of time. - View Dependent Claims (27)
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Specification