Class notes
CHAPTER 2
- Institution
- Central University Of Technology (CUT)
Lecture notes of 46 pages for the course Electrical Engineering at CUT (DIGITAL SYSTEMS 2)
[Show more]
Seller
Follow
Content preview
LatchesA latch is a temporary storage device that has two
stable states (bistable). It is a basic form of memory.
The S-R (Set-Reset) latch is the most basic type. It can be constructed
from NOR gates or NAND gates. With NOR gates, the latch responds to
active-HIGH inputs; with NAND gates, it responds to active-LOW inputs.
, Latches
The active-HIGH S-R latch is in a stable (latched) condition
when both inputs are LOW.
0 R 1
0
Assume the latch is initially RESET Q
(Q = 0) and the inputs are at their Latch
inactive level (0). To SET the latch initially
(Q = 1), a momentary HIGH signal RESET
0
1
is applied to the S input while the R Q
0 S
remains LOW.
0 R 1
0
To RESET the latch (Q = 0), a Q
momentary HIGH signal is Latch
applied to the R input while the S initially
remains LOW. SET
1
0
Q
0 S
, Latches
The active-LOW S-R latch is in a stable (latched) condition
when both inputs are HIGH.
Assume the latch is initially RESET 1 S 1
0
Q
(Q = 0) and the inputs are at their
Latch
inactive level (1). To SET the latch initially
(Q = 1), a momentary LOW signal RESET
is applied to the S input while the R 1
0
1 R Q
remains HIGH.
To RESET the latch a momentary 1 S 1
0
Q
LOW is applied to the R input
Latch
while S is HIGH. initially
Never apply an active set and 1 SET
0
Q
reset at the same time (invalid). 1R
, Latches
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller shillamathwasa. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R133,00. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
79223 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now