The CS61584 Dual T1/E1 LIU has been modified and improved to create the CS61584A. The CS61584A has all of the features and performance of the CS61584, plus many additional features. Incorporating these improvements made it necessary to make several changes to the pinout and functionality which the user must account for when upgrading to the CS61584A. When reviewing the following information, refer to Table 1 for a description of the pinout changes and to Table 2 for changes to the timing specifications.