Robust local bit select circuitry to overcome timing mismatch

摘要

An integrated circuit can include an SRAM array having cells arranged in columns, each column being connected to true and complementary read local bitlines RLBLT and RLBLC. A local bit-select circuit can be connected to the cells of a column of the SRAM array, which can include first and second pull-down devices for pulling down a respective one of RLBLT and RLBLC at a timing controlled by a write control signal WRT. The circuit can include cross-coupled p-type field effect transistors (“PFETs”) including a first PFET having a gate connected to RLBLT and having a drain connected to RLBLC, and a second PFET of the pair having a gate connected to RLBLC and having a drain connected to RLBLT. A first device can control a strength of the cross-coupled PFETs. A pair of cross-coupled n-type field effect transistors (“NFETs”) can have gates connected to gates of the first and second pull-down devices. A second device can control a strength of the cross-coupled NFETs. The operation of the first and second devices can be controlled by applying first and second signals having programmed levels thereto. The levels of the first and second signals may selectively activate either the first device or the second device, so as to activate either the cross-coupled PFETs or the cross-coupled NFETs at one time.