Programmable Logic Device
What is Plds
-programmable is a logic device, or PLDS, are microcelectronic devices that
devices that programme and repogrammed to perform a variety of Logic
Logic operations
They are reconfigurable circuits that cam allow designers to implement
implement custome logic circuits.
PLDS have a wide-range of applications
Field programmable gate Array
PLDS includes devices like FPGAS of Complex programmable logic devices
devices (CPLDS)
PLDE Offers flexibility of efficiency in the digital world of design
Types of Programmable Logic Devices
1. Read only memories (ROMs)
2. Programmable Logic Array (PLAs)
3. Simple Programmable Logic Devices (SPLDs)
(SPLDs)
4. Complex Programmable Logic Devices (CPLDsl
(CPLDsl
6. The most popular type of PLD that allows for complex logic and
5. Field
logic and IP inProgrammable
integration. Gate Arrays (FPGAs).
Advantages of using Programmable Logic
Logic Devices
1. They need less amount of space.
2. They need less power for operation.
3. Their speed of switching is high.
4. They ensure higher security (copying is less likely to take
take place).
5. PLDS have higher component density.
6. PLDs can be produced at lower costs.
7. PLDs have lower development cost as well
8. The time required to implement the design is short.
9. PLDS provide more flexibility to the designer.
10. It is possible to reprogram PLDs very quickly.
Applications of Programmable Logic Devices
Devices
1 Wireless Communication
PLDs are used in wireless communication devices like WiFi routers and base stations to perform logic
and protocol functions.
2 Robotics
PLDs are used in robotic systems to control movement and interface with sensors and other
equipment.
3 Industrial Control Systems
PLDs are used in industrial control systems like motor control to perform logic operations and
interface with sensors and other equipment.
About Programmable Logic Devices
The logic gates used in a PLA can be the two level logic
configurations of AND-OR, NAND-NAND or NOR-NOR types.
Sometimes AND-OR-EXOR configuration is also used. In Fig.
11.3.1 the two level AND-OR configuration is being used.
There are two types of PLDs namely the PLA i.e.
programmable logic arrays and PAL i.e. the programmable
array logic. As shown in Fig. 11.3.1 the AND matrix is followed
by OR matrix. Therefore, we can use PLA or PAL for the
implementation of logic functions that are expressed in the
SOP form.
A PLA as shown in Fig. 11.3.1, consists of two level AND- OR
configuration. The inputs are applied to the AND matrix
through input buffers and the output of AND matrix is applied
to the OR matrix.
Limitations of Programmable Logic Devices
Power Consumption Design Time Security
PLDs can consume a lot of power, Designing with PLDs can be time- PLDs may be less secure than
which can be challenging for consuming because of the need ASICs because they are
battery-powered devices. for programming and verification. reprogrammable and can
potentially be hacked or
tampered with.
Future Trends in Programmable Logic Devices
Smart Home Technology Quantum Computing Medical Devices
PLDs could be used in smart home PLD technology could be used in PLDs could be used in medical
devices to perform logic operations quantum computing systems to devices to perform logic operations
and interface with sensors and interface with sensors and other and interface with sensors and
other equipment. equipment. other equipment.
