PARALLEL/SERIAL SCAN SYSTEM FOR TESTING LOGIC CIRCUITS

Abstract

A testable logic circuit includes parallel registers (72)-(80) for interfacing with a common internal bus (70). The parallel registers (72)-(80) are individually addressable by an address decoder (104) for storage of test vectors therein. These test vectors are then applied to associated logic circuits. Individual shift register latches (92)-(102) are provided at imbedded locations therein. The shift register latches are interfaced with a serial data link to allow serial loading of data therein. The parallel latches function in both the test mode to store test vectors for application to the associated logic and also in the operational mode for storage of logic data. Use of parallel registers increases the speed at which data is scanned into the device.

Source: Google Patents

35 USC §181 Secrecy Order

Inventor

• 1THEO J. POWELL