SYSTEMS AND METHODS FOR WAFER-LEVEL LOOPBACK TEST

摘要

Circuits and methods for loopback testing are provided. A die incorporates a receiver (RX) to each transmitter (TX) as well as a TX to each RX. This architecture is applied to each bit so, e.g., a die that transmits or receives 32 data bits during operation would have 32 transceivers (one for each bit). Focusing on one of the transceivers, a loopback architecture includes a TX data path and an RX data path that are coupled to each other through an external contact, such as a via at the transceiver. The die further includes a transmit clock tree feeding the TX data path and a receive clock tree feeding the RX data path. The transmit clock tree feeds the receive clock tree through a conductive clock node that is exposed on a surface of the die. Some systems further include a variable delay in the clock path.

主权项

1. A circuit comprising:
a die having a plurality of bits, each bit having:
a transmit data path and a receive data path;a transmit clock tree feeding the respective transmit data path of each bit; anda receive clock tree feeding the respective receive data path of each bit; wherein the transmit clock tree feeds the receive clock tree through a conductive clock node exposed on a surface of the die.