The document discusses programmable logic devices (PLDs), their history, purpose, advantages, and types, including simple PLDs and high capacity PLDs like CPLDs and FPGAs. It highlights the programmability and cost-effectiveness of PLDs, making them suitable for digital logic design and prototyping. The document also outlines the configuration requirements and memory types used in PLDs.

1. Programmable Logic Devices
ABIRAMI K
120040001
M.TECH-VLSI DESIGN
SASTRA DEEMED TO BE UNIVERSITY
SWAYAM APPLICATION ID:
a3f17cabee8f11e98f1ef3ce5536c308

2. Road Map
• History
• Definitions
• Programmable Logic Devices
– Purpose
– Advantages
– Types
• Configuration
• Conclusion

3. History
• Programmable logic arrays – about 1970
• Programmable logic devices – about 1980
• Field Programmable Gate Arrays – about 1985
– Xilinx Logic Cell Array

4. Definitions
• Programmable Logic Device (PLD):
– Also known as “Field Programmable Logic Device
(FPLD)”
– An integrated circuit chip that can be configured
by the user to implement different digital
hardware.

5. Purpose of PLDs
• Permits elaborate digital logic designs to be
implemented by the user on a single device.
• Is capable of being erased and reprogrammed
with a new design.

6. Advantages of PLDs
• Cost effective in lower
volumes
• Short design time
• Well suited for academics
and prototyping
PLD
Volume
ASIC
Cost
(Application Specific
Integrated Circuit)

7. Advantages of PLDs
• Programmability
• Re-programmability
– PLDs can be reprogrammed without being
removed from the circuit board.
• Low cost of design
• Immediate hardware implementation

8. Types of PLDs
• SPLDs (Simple Programmable Logic Devices)
– ROM (Read-Only Memory)
– PLA (Programmable Logic Array)
– PAL (Programmable Array Logic)
– GAL (Generic Array Logic)
• HCPLD (High Capacity Programmable Logic Device)
– CPLD (Complex Programmable Logic Device)
– FPGA (Field-Programmable Gate Array)

9. Types of PLDs (Cont.)
PLD
SPLD
ROM PLA PAL GAL
HCPLD
CPLD FPGA

10. SPLDs
• In ROM, the input connection matrix is
hardwired and the user can only modify the
output connection matrix.
• In PAL and GAL the output connection matrix
is also hardwired and the user can modify the
input connection matrix.
• In PLA the user can modify both the input
connection matrix and the output connection
matrix.

11. HCPLDs
• CPLD (Complex Programmable Logic Device)
– Lies between PALs and FPGAs in degree of
complexity.
– Inexpensive
• FPGA (Field-Programmable Gate Array)
– Truly parallel design and operation
– Fast turnaround design
– Array of logic cells surrounded by programmable
I/O blocks

12. FPGA Design

13. PLD Configuration
• Combination of a logic device and memory
• Memory stores the pattern the PLD was
programmed with
– EPROM
• Non-volatile and reprogrammable
– EEPROM
• Non-volatile and reprogrammable
– Static RAM (SRAM)
• Volatile memory
– Flash memory
• Non-volatile memory
– Antifuse
• Non-volatile and no re-programmability

14. Configuration (cont.)
Name Re-Programmable Volatile
SRAM Yes Yes
FLASH Yes No
EPROM Yes (out of the circuit) No
EEPROM Yes (in the circuit) No
Antifuse No No

15. Conclusion
• History
• Definitions
• Programmable Logic Devices
– Purpose
– Advantages
– Types
• Configuration

16. References
"Complex Programmable Logic Devices (CPLD) Information." On GlobalSpec.
N.p., n.d. Web. 6 Apr. 2013.
<http://www.globalspec.com/learnmore/analog_digital_ics/program
mable_logic/complex_programmable_logic_devices_cpld>.
"Computer History Museum - The Silicon Engine | Search." Computer History
Museum - The Silicon Engine | Search. N.p., n.d. Web. 06 Apr. 2013.
<http://www.computerhistory.org/semiconductor/search.html?search=F
PGA>.
"FPGA - Field Programmable Gate Array." Welcome to FPGA Central. N.p., n.d.
Web. 06 Apr. 2013. <http://www.fpgacentral.com/pld-types/fpga-
field-programmable-gate-array>.
"Fpga4fun.com - What Are FPGAs?" Fpga4fun.com - What Are FPGAs? N.p.,
n.d. Web. 06 Apr. 2013<http://www.fpga4fun.com/FPGAinfo1.html>.
Gaganpreet, Kaur. VHDL: BASICS TO PROGRAMMING. N.p.: Pearson Education,
2011. Print.
"What Is an FPGA?What Does a Logic Cell Do?So What Does 'Field
Programmable' Mean?How Are FPGA Programs Created?" FPGA Basics.
N.p., n.d. Web. 06 Apr. 2013. <http://www.andraka.com/whatisan.htm>.