Code-Mapping Program Using a Microprocessor Single-Step Mode
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
To insure adequate testing of a product code under test, a mapping system verifies the instructions in the product code under test that were executed as a result of running each test. An Intel 8088 microprocessor has a trap flag that causes it to operate in a single-step mode. When this flag is set, acode mapping program is executed after the execution of each instruction in the product code. The code-mapping program sets a bit in a 4K array of eight-bit bytes in a portion of the memory of the product under test with each byte corresponding to a byte of the product code being executed. The map printout is a matrix of 1's and 0's with one digit for each byte of the product code. A 1 in the printout indicates an instruction was executed.