The TX Phase Interpolator Parts Per Million (TXPIPPM) Controller module provides support for dynamically controlling the TX phase interpolator (TX PI). Located in the TX PCS, its inputs come from the TX interface and it outputs to the TX PMA. Applications exist that require fine-tune control of the data in the TX PMA. Control of the output clock from the PLL is achieved through a TX PI, which in turn can be controlled by the TX phase interpolator PPM controller module. The interconnect logic can control the TX PI in the TX PMA through the use of the TX phase interpolator PPM controller module in the PCS. The TX phase interpolator PPM controller module is only supported for line rates up to 16.375 Gb/s.