Embodiments of the present invention enable the matching of pull-up and
pull-down driver strengths of a slave device (DDRII SDRAM), i.e., the P-channel/N-channel
driver pull-up/pull-down Ron and also calibrates the P-channel/N-channel pull-up/pull-down
drivers in their linear region of operation. Specifically, embodiments of the present
invention may use the DDR-II Off Chip Driver (OCD) protocol for calibration, in
addition to using circuit techniques to calibrate the slave driver pull-up Ron
within 1 LSB of the pull-down Ron.