A boundary scan cell for use in a circuit having a boundary scan shift
register (BSSR) having boundary scan cells associated with pins of the
circuit, the cell having a single-bit shift register element and an
associated update latch, comprises a logic circuit for controlling the
logic state of an associated pin, analog switches connecting the
associated pin to analog test buses, and logic circuitry for selectively
configuring the cell in a parametric test mode in which the cell shift
register element controls the analog switches, and in a digital test mode
in which the cell shift register element controls the logic state of the
associated pin.