US 5,063,383 A · System and method for testing analog to digital converter embedded in microcontroller

Abstract

A tester system tests the transfer characteristics and operability of an analog to digital converter (ADC) embedded in a microprocessor. The tester generates a sequence of analog signal test values, and prompts the microprocessor to read and convert each test value. The microprocessor sets up a table in its internal memory, the table having one tally value for every possible code output by the embedded ADC. After the embedded ADC converts each test value, the microprocessor reads the digital value output by the embedded ADC and increments a corresponding tally value in its internally stored table. When the sequence of tests is completed, the microprocessor transmits the entire table of tally values to the tester. The tester then performs a well known set of calculations on the tally data to determine the transfer characteristics and operability of the embedded ADC. By performing all tally operations in the microprocessor under test, the test sequence can be performed much more quickly than if each converted value were separately transmitted by the microprocessor to the tester. In addition, the tallying operation of the microprocessor simulates normal operation of the microprocessor while performing analog to digital conversions, and thus the embedded ADC is subjected to electromagnetic noise characteristic of the microprocessor under normal operation.

Claims16

Dependent claims

A method of testing an analog to digital converter (ADC) embedded in a microprocessor, said embedded ADC generating a predefined number of distinct, digital output values when converting input analog signals, said microprocessor having a random access memory embedded in said microprocessor for storing data values and program means coupled to said microprocessor for storing software which controls the operation of said microprocessor, the steps of the method comprising:

storing in said microprocessor's program mean a data tallying control program;
generating a sequence of analog test signals within a predefined range and transmitting said analog test signals to said embedded ADC;
said embedded ADC converting each said analog test signal and generating a digital output value;
said microprocessor, under control of said data tallying control program, tallying said digital output values generated by said embedded ADC and storing corresponding tally values in said microprocessor's embedded random access memory;
and
after said sequence of analog test signals has been transmitted and converted, transmitting said tally values stored in said embedded random access memory in said microprocessor to a tester, and then evaluating said tally values in said tester.

3 more elements

The method of testing an analog to digital converter (ADC) embedded in a microprocessor, said embedded ADC generating a predefined number of distinct, digital output values when converting input analog signals, said microprocessor having a random access memory embedded in said microprocessor for storing data values and program means coupled to said microprocessor for storing software which controls the operation of said microprocessor, the steps of the method comprising:

storing in said microprocessor's program mean a data tallying control program;
said microprocessor, under the control of said data tallying control program, defining in said embedded random access memory in said microprocessor a table having tally entries for storing a multiplicity of tally values, each said tally entry in said table corresponding to a distinct, digital output value generated by said embedded ADC;
generating a sequence of analog test signals within a predefined range and transmitting said analog test signals to said embedded ADC;
said embedded ADC converting each said analog test signal and generating a digital output value;
said microprocessor, under control of said data tallying control program, incrementing said tally value stored in said table entry corresponding to said digital output value generated by said embedded ADC;
and
after said sequence of analog test signals has been transmitted and converted, transmitting said table of tally values stored in said embedded random access memory of said microprocessor to a tester, and then evaluating said tally values in said tester;
whereby tally values are accumulated in random access memory embedded in said microprocessor, which enables fast testing of the embedded ADC.

5 more elements

Test apparatus for testing an analog to digital converter (ADC) embedded in a microprocessor, said embedded ADC generating a predefined number of distinct, digital output values when converting input analog signals, said microprocessor having a random access memory for storing data values, the test apparatus comprising:

a data processing unit coupled to an analog signal generator, said data processing unit and analog signal generator generating a sequence of analog test signals within a predefined range and transmitting said analog test signals to an embedded ADC in a microprocessor;
said data processing unit and analog signal generator including means for generating a prompting signal which causes said embedded ADC to convert each said analog test signal into a digital output value;
and
program means coupled to said microprocessor for directing said microprocessor to store and accumulate in said random access memory in said microprocessor data corresponding to said digital output values output by said embedded ADC;
said program means including software for directing said microprocessor to transmit said data stored in said random access memory in said microprocessor to said data processing unit after said sequence of analog test signals has been converted by said embedded ADC;
said data processing unit including software for evaluating said data accumulated and stored in said microprocessor and transmitted by said microprocessor to said data processing unit;
whereby data resulting from testing of said embedded ADC is accumulated in random access memory in said microprocessor, which enables fast testing of the embedded ADC.

4 more elements

a data processing unit coupled to an analog signal generator, said data processing unit and analog signal generator generating a sequence of analog test signals within a predefined range and transmitting said analog test signals to an embedded ADC in a microprocessor;
said data processing unit and analog signal generator including means for generating a prompting signal which causes said embedded ADC to convert each said analog test signal into a digital output value;
and
program means coupled to said microprocessor for defining in said random access memory in said microprocessor a table having entries for storing a multiplicity of tally values, each said entry in said table corresponding to a distinct, digital output value generated by said embedded ADC;
said program means directing said microprocessor to increment said tally value stored in said table entry corresponding to each said digital output value generated by said embedded ADC;
said program means further including software for directing said microprocessor to transmit said tally values stored in said random access memory in said microprocessor to said data processing unit after said sequence of analog test signals has been converted by said embedded ADC;
said data processing unit including software for evaluating said data accumulated and stored in said microprocessor and transmitted by said microprocessor to said data processing unit;
whereby said tally values are accumulated in random access memory in said microprocessor, which enables fast testing of the embedded ADC.

5 more elements

Dependencies are inferred from the claim text.

System and method for testing analog to digital converter embedded in microcontroller

Life of this patent

System and method for testing analog to digital converter embedded in microcontroller

Life of this patent

Abstract

Claims16