Download presentation
Presentation is loading. Please wait.
Published byElla Beasley Modified over 9 years ago
1
درس مدارهای منطقی دانشگاه قم http://lc-qom.blogfa.com/ Programmable Logic (PAL, PLA) تهیه شده توسط حسین امیرخانی مبتنی بر اسلایدهای درس مدارهای منطقی دانشگاه امیرکبیر http://ceit.aut.ac.ir/~szamani/index_files/logic.htm
2
Symbols for OR gate 2
3
3 PLA (Programmable Logic Array)
4
4 PLA A 3×2 PLA with 4 product terms
5
5 PLA Pre-fabricated building block of many AND/OR gates (or NOR, NAND) General purpose logic building blocks “Personalized” or “customized” by making/ breaking connections among the gates This process is called “programming”
6
6 PLA Sums of Products
7
7 Design for PLA: Example Implement the following functions using PLA Personality Matrix 1 = asserted in term 0 = negated in term - = does not participate Input Side: 1 = term connected to output 0 = no connection to output Output Side: OutputsInputsProduct term A 1 - 1 - 1 B 1 0 - 0 - C - 1 0 0 - F 0 0 0 0 1 1 F 1 1 0 1 0 0 F 2 1 0 0 1 0 F 3 0 1 0 0 1 A B B C A C B C A
8
8 Personality Matrix OutputsInputsProduct term A 1 - 1 - 1 B 1 0 - 0 - C - 1 0 0 - F 0 0 0 0 1 1 F 1 1 0 1 0 0 F 2 1 0 0 1 0 F 3 0 1 0 0 1 A B B C A C B C A Design for PLA: Example
9
9 Constants Sometimes a PLA output must be programmed to be a constant 1 or a constant 0. Manufacturer MAY pull up the AND inputs: − P1 is always 1 is pulled UP or HIGH. − This constant 1 term drives the O1 output. Manufacturer MAY pull down the OR inputs: − O2 is 0. Anot her method of obtaining a constant-0 output is shown for O3.
10
10 PAL (Programmable Array Logic) Sums of Products but with a fixed OR array
11
11 PAL inputs 1 st output section 2 nd output section 3 rd output section 4 th output section Only functions with at most four products can be implemented
12
12
13
13 PAL W = ABC + CD X = ABC + ACD + ACD + BCD Y = ACD + ACD + ABD x x x
14
14
15
Final Remark 15 A Programmable Logic achieves higher flexibility at the cost of lower speed!
16
تمرینهای آزمون ارشد سؤالسال 131380 641386 681388 16
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.