Patent ID: 7746795
Filing Date: 2010-06-29
Classification: H04L

Abstract:
1. An apparatus for a loopback test configured for a master device and a slave device connected via a layered point-to-point interface with a layered interface comprising: a state machine within the master device having a dedicated state for the loopback test in a link layer state diagram; a loopback control register to allow the master device to set the electrical parameters for the loopback test to be transmitted to the slave device, wherein the slave device is configured to transmit data back to the master device as part of the loopback test wherein the master-slave loopback scheme is controlled by a physical layer of the master device that controls the exchange of the electrical parameters between the master device and the slave device over the layered point-to-point interface having one or more physical layer hooks and registers to enable higher-level self-testing, and wherein the electrical parameters comprise at least an offset value for an offset controlled transmit amplifier; and a loopback status register to store a result of the loopback test.