Area-efficient configuration latch for programmable logic device

Abstract

An area efficient input terminated readable and resettable configuration memory latch is disclosed. A pull-up network and a pair of pull-down networks operate to set the value of an internal node based, in part, on the state of the input terminated bit line and a word line write input. The internal node is inverted to form the output of the configuration memory latch. A reset line operates to reset the latch and a reset cycle is initiated prior to each write cycle. In some embodiments, the configuration memory latch includes a scan mode input, which, when asserted, facilitates automated testing of a programmable logic device that includes the configuration memory latch. Asserting the scan mode input enables Design for Test functionality. A sensing block is configured to sense the state of the bit when a word line read signal and a read enable signal are both asserted.