Abstract:
A dual-purpose I/O circuit for use in an integrated circuit having a primary circuit is provided. The dual-purpose I/O circuit includes two conducting pads, two single-ended I/O cells and one differential I/O cell. Several dual-purpose I/O circuits can be used within a single integrated circuit to support both single-ended and/or differential mode I/O signaling between external circuits and devices and a primary circuit within the integrated circuit. Within each dual-purpose I/O circuit, a first single-ended I/O cells is connected to a first conducting pad, a second single-ended I/O cell is connected to the second conducting pad and a differential I/O cell is connected to the both the first single-ended and second single-ended I/O cells and to both the first and second conducting pads. A control logic is connected to at least one of the first single-ended, second single-ended and differential I/O cells. The control logic is arranged to selectively enable and disable at least one of the first single-ended, second single-ended and differential I/O cells.