A Novel ODT Selection for Memory Data Bus of Daisy Chain Topologies

This study presents a novel analytical method for determining the value of on-die-terminator (ODT) used in daisy-chain topologies. The analytical method is utilized by the transmission coefficient to determine receiving power. While in conventional methods, the receiving power is determined by the reflection coefficient. This study demonstrates that the reflection coefficient is not suitable to determine the ODT values directly. An optimization algorithm is presented to select the ODT value for the un-access Dual Inline Memory Module (DIMM). The selected ODT value improves power efficiency due to increase the bit width and decrease the overshoots. The magnitude and width of eye pattern are improved 300 mv and 10 ps by changing the ODT value from 20 to 75 ohm in both write and read states.