- Log Out
- Settings
- My Profile
- Notifications
  - No new messages
  - Inbox
- Welcome, neazoi

+ Post New Thread + Reply to Thread + Mark as Solved
Results 1 to 2 of 2

# Thread: 8-to-255 address decoder out of ttl

- ###### LinkBack

  - LinkBack URL
  - About LinkBacks
  - Bookmark & Share
  - Digg this Thread!
  - Add Thread to del.icio.us
  - Bookmark in Technorati
  - Tweet this thread

- ###### Thread Tools

  - Show Printable Version
  - Email this Page…
  - Download This Thread
  - Subscribe to this Thread…
  - Mark this thread as solved…

- ###### Search Thread

  - Advanced Search

1. Today, 14:31 #1
   neazoi
   - View Profile
   - View Forum Posts
   - Private Message
   - View Blog Entries
   - Visit Homepage
   - View Articles
   - Give Away Points
   Advanced Member level 2

   Join Date
     Jan 2008
   Location
     Greece
   Posts
     691
   Helped
     8 / 8
   Points
     4,802
   Level
     16

   ## 8-to-255 address decoder out of ttl

   > Hello,
   > I need to make a 8 to 255 decoder for educational pusposes out of ttl.
   > I am thinking of using the 74ls154 on the next scheme:
   > 1. One 74ls154 decodes 4 to 16.
   > 2. It's inputs, will be the 4 lower bits on the total of 8 of the decoder.
   > 3. Each of the 16 outputs of this first 74ls154, is connected to the enable pins (G1, G2, active low) of each of another 16 74ls154 ICs.
   > 4. All 4 inputs of these other 16 74ls154 will be connected together in parallel (common bus).
   > 5. These 4 inputs will be the 4 higher bits on the total of 8 of the decoder.
   > Will this work?
   > If yes, I guess I need just 17 of these 74ls154 ICs?

   Edit Post Reply Reply With Quote Multi-Quote Msg Report Post View Profile Private Message

2. Today, 14:38 #2
   betwixt
   - View Profile
   - View Forum Posts
   - Private Message
   - View Blog Entries
   - Visit Homepage
   - View Articles
   - Add as Contact
   - Send Email
   Advanced Member level 5

   Join Date
     Jul 2009
   Location
     Aberdyfi, West Wales, UK
   Posts
     2,873
   Helped
     884 / 884
   Points
     19,869
   Level
     34

   ## Re: 8-to-255 address decoder out of ttl

   > That is correct and also the minimum number of ICs to complete the task.
   > Essentially, the bottom 4 bits provide 1 of 16 selections on all the output ICs simultaneously but the top 4 bits ensure that only one of them is enabled at a time.
   > Brian.

   > I always try to help Edaboard members but I get hundreds of private emails every day so please ask here rather than privately and do not be offended if I reject 'friend' requests.

   Did you find this post helpful? Click:
   Reply Reply With Quote Multi-Quote Msg Report Post View Profile Private Message Give Points Add as Contact

+ Post New Thread + Reply to Thread + Mark as Solved
Quick Navigation Electronic Elementary Questions Top

- Site Areas
- Settings
- Private Messages
- Subscriptions
- Who's Online
- Search Forums
- Forums Home
- Forums
- EDA Theory
  1. Electronic Elementary Questions
- EDA Software
  1. Software Links
  2. Software Requests
  3. Software Problems, Hints and Reviews
  4. Linux Software
- Digital Design and Programming
  1. ASIC Design Methodologies and Tools (Digital)
  2. PLD, SPLD, GAL, CPLD, FPGA Design
  3. Microcontrollers
  4. Digital Signal Processing
  5. Embedded Systems and Real-Time OS
  6. PC Programming and Interfacing
  7. Network
  8. Digital communication
- Analog Design
  1. Analog Circuit Design
  2. Analog IC Design and Layout
  3. RF, Microwave, Antennas and Optics
  4. Electromagnetic Design and Simulation
  5. Power Electronics
  6. Tubes and Retro
- Hardware and PCB Design
  1. Show DIY
  2. Hobby Circuits and Small Projects Problems
  3. Professional Hardware and Electronics Design
  4. PCB Routing Schematic Layout software and Simulation
  5. Robotics and Automatics Forum
  6. Service Manuals, Requests, Repair Tips
  7. Mechanical Engineering and Design
  8. Other Design
- Science
  1. Mathematics and Physics
  2. Heuristic methods, Machine Learning, AI, and Soft Computing
- General Computer
  1. General Computer
- Others
  1. About EDAboard.com
  2. EDA Jobs, Promotions, Advertising
  3. Business Special Interest Group
  4. Off Topic Chat
  5. Trashcan

## vBulletin Message

Cancel Changes

### Errors

### The following errors occurred with your submission

Okay

### Quick Reply

Rich Text Editor

Editor Toolbars Remove Format Paste as plain text Bold Italic Underline Font Font Size Size Text Color Smiley Link Email Unlink Insert Image Insert Video Wrap [QUOTE] tags around selected text Wrap [CODE] tags around selected text Wrap [HTML] tags around selected text Wrap [PHP] tags around selected text
Auto-Saved

Posting Quick Reply - Please Wait Add an Image

- Attachments:

« capacitor circuit doubt | - »

#### Similar Threads

1. ###### What does 32 x 32 memory address decoder mean? (5)

2. ###### hex inverter out of discrete RTL or TTL (7)

3. ###### 1-bit ALU design out of TTL gates (0)

4. ###### Address decoder logic for 15-bit addresses (0)

5. ###### Simple address decoder problem. (2)