US 10,890,623 B1
Power saving scannable latch output driver
William Huott, Holmes, NY (US); Yuen Chan, Poughkeepsie, NY (US); Pradip Patel, Poughkeepsie, NY (US); and Daniel Rodko, Poughkeepsie, NY (US)
Assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION, Armonk, NY (US)
Filed by International Business Machines Corporation, Armonk, NY (US)
Filed on Sep. 4, 2019, as Appl. No. 16/559,776.
Int. Cl. G01R 31/28 (2006.01); G01R 31/3185 (2006.01); H03K 19/00 (2006.01)
CPC G01R 31/318541 (2013.01) [G01R 31/31855 (2013.01); G01R 31/318572 (2013.01); G01R 31/318575 (2013.01); H03K 19/0016 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
receiving, by a circuit comprising a scannable latch, a scan signal;
based on the scan signal being enabled, turning on a scan output driver of the scannable latch, wherein a scan input of the scannable latch propagates through the scannable latch to a scan output based on the scan output driver being turned on; and
based on the scan signal being disabled, turning off the scan output driver, wherein the scan output driver comprises a first p-type field effect transistor (PFET) and a first n-type field effect transistor (NFET), wherein a gate of the first PFET and a gate of the first NFET are connected to an output of a latch of the scannable latch.