| abstract |
Portable tester and method for testing a variety of printed circuit boards without utilizing specialized adaptor boards for rerouting input test signals and supply voltages from the tester to various pins of the board under test. A plurality of edge connectors have their respective pins connected to corresponding edge connector stake pins. Each edge connector stake pin is connected to or isolated from the corresponding driver/sensor stake pin by means of a switch. Each driver/sensor stake pin is connected to the input/output terminal of a programmable driver/sensor circuit. A main processor is utilized to store a test program and to transmit data and control information to predetermined driver/sensor circuits. A high speed processor coupled between the main processor and the inputs of the driver/sensor circuits includes a parallel-loadable shift register, an instruction register, an instruction decoder and control circuitry connected to the inputs of the driver/sensor circuitry. The high speed processor memory can store a bus-defining subroutine containing a sequence of data shifting instructions which shift a word in the shift register to the input of driver/sensor circuits specified by the arguments of the shifting instruction at high speed, thereby achieving high speed routing of data from the main processor to the board under test with very few instructions of the test program. Each driver/sensor circuit has programmable pull-up and pull-down termination devices which obviate the need for certain termination resistors on the board under test. |