Memory interface device and method for supporting debugging

Abstract

An integrated circuit memory interface device includes a debug controller for generating debug control signals in response to memory access control signals, and individual address and data boundary-scan registers. Each of the address and data boundary-scan registers has a predetermined number of cells which are daisy-chained from cell to cell. The address and data registers are placed between a memory device and a core logic which performs normal interface operations with respect to the devices during a normal mode. The interface device includes a test access port (TAP) controller which operates in synchronism with a test clock signal during test and debugging modes, and an instruction register. The TAP controller receives a test mode select signal and generates register control signals in response to the test clock and mode select signals. The instruction register receives a test/debug instruction via the serial boundary-scan test data input port and generates memory access control signals in response the test/debug instruction.