The present invention provides a method of providing two different
modes of operation for an output driver on an
integrated circuit. A first mode provides an open drain driver, such as an enhanced GTL+ driver, for high-speed
data transmission. A second mode provides a totem pole output driver, such as a TTL or a LVTLL driver, which does not require additional circuitry for external terminations, as is required for open drain drivers. Thus, one embodiment of the present invention can be characterized as a method of providing a
dual mode output from an
integrated circuit. This method includes receiving an output mode
signal indicating an enhanced GTL+ output mode or a totem pole output mode. This method also includes providing an enhanced GTL+ output
signal if the mode
signal indicates the enhanced GTL+ output mode, and providing a totem pole output signal if the mode signal indicates the totem pole output mode. Another embodiment of the present invention can be described as a method for providing a
dual mode output from an
integrated circuit. This method includes providing to the integrated circuit an output mode signal indicating a first output mode or a second output mode. It also includes
coupling an output pin of the integrated circuit to an open drain
bus with an active termination if the mode signal indicates the first mode, and
coupling an output pin of the integrated circuit to an unterminated
bus if the mode signal indicates the second output mode.