DO-CPLD-DK-G Xilinx Inc, DO-CPLD-DK-G Datasheet - Page 11

• Manufacturer Part Number: DO-CPLD-DK-G
• Description: KIT DESIGN CPLD W/BATT HOLDER
• Manufacturer: Xilinx Inc
• Series: CoolRunner™- IIr
• Type: CPLDr

Specifications of DO-CPLD-DK-G

• Contents: Proto Board, Download Cable, Samples, Software
• For Use With/related Products: CoolRunner-ll, XC9500XL
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 122-1512

The History of Programmable Logic
Programmable Logic Design
June 12, 2006
R
Introduction
By the late 1970s, standard logic devices were all the rage, and printed circuit boards were
loaded with them. Then someone asked, “What if we gave designers the ability to
implement different interconnections in a bigger device?” This would allow designers to
integrate many standard logic devices into one part.
To offer the ultimate in design flexibility, Ron Cline from Signetics (which was later
purchased by Philips and then eventually Xilinx) came up with the idea of two
programmable planes. These two planes provided any combination of “AND” and “OR”
gates, as well as sharing of AND terms across multiple ORs.
This architecture was very flexible, but at the time wafer geometries of 10 µm made the
input-to-output delay (or propagation delay) high, which made the devices relatively
slow. The features of the PLA were:
•
•
•
•
•
•
Two programmable ground planes
Any combination of ANDs/ORs
Sharing of AND terms across multiple ORs
Highest logic density available to user
High fuse count; slower than PALs
Programmable logic array
A
A
Indicates ‘used’ junction
Indicates ‘used’ junction
Indicates ‘unused’ junction
Indicates ‘unused’ junction
Indicates ‘unused’ junction
Indicates ‘fixed’ junction
Indicates ‘fixed’ junction
Indicates ‘fixed’ junction
Inputs
Inputs
B
B
C
C
www.xilinx.com
Figure 1-1: Simple PLA
Outputs do not have dedicated product terms
Outputs do not have dedicated product terms
X
X
Common logic shared
Common logic shared
Outputs
Outputs
Y
Y
Only requires 3 pt’s
Only requires 3 pt’s
X = A & B # C
X = A & B # C
Y = A & B # !C
Y = A & B # !C
Chapter 1
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