180 likes | 328 Views
The George Washington University School of Engineering and Applied Science Department of Electrical and Computer Engineering. ECE122 – Lab 6 Latches & Flip-flops. Jason Woytowich October 7, 2005. Latches & Flip-flops. Single bit memory elements
E N D
The George Washington UniversitySchool of Engineering and Applied ScienceDepartment of Electrical and Computer Engineering ECE122 – Lab 6 Latches & Flip-flops Jason Woytowich October 7, 2005
Latches & Flip-flops • Single bit memory elements • Latches change state whenever the inputs dictate it • Flip-flops only change state on rising or falling clock edges
SR Latch • Set/Reset Latch
SR Latch • NOR Implementation
SR Latch • NAND Implementation
D Latch • A Gated Latch
D Latch • An SR Latch implementation
D Flip-Flop • The value of D is stored on either the rising or falling clock edge. Clock D Q
DFF • Master-Slave Implementation
DFF • Gate Trigger Implementation
Positive Gate Trigger There are an odd number of inverters.
Lab Activities • Build and test an SR Latch from NAND Gates • Build and test a D Latch from the SR Latch • Build and test a DFF from your D Latch, MS or PGT
Homework • Build a 4-bit incrementer • Put DFFs on the inputs and outputs • Find how fast you can drive the clock without producing errors