The MPC903, MPC904 and MPC905 are six output clock generation devices targeted to provide the clocks required in a 3.3V or 5.0V PCI environment. The device operates from a 3.3V supply and can interface to either a TTL input or an external crystal. The inputs to the device can be driven with 5.0V when the VCC is at 3.3V. The outputs of the MPC903/904/905 meet all of the specifications of the PCI standard. The three devices are identical except in the function of the Output Enables.