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GAL,PAL,PLD, CPLD,FPGA

G

Guest

Jan 1, 1970
0
GAL,PAL,PLD, CPLD,FPGA, (what else...?)

GAL : Generic Logic Array
PAL : Programmable Array Logic
PLD : Programmable Logic Device
CPLD : Complex Programmable Logic Device
FPGA : Field Programmable Gate Array

Can someone explain with comparison what is the difference between all these
GAL,PAL,PLD, CPLD,FPGA, (what else...?) logic units?

Can all these units can be programmable with VHDL ?
 
M

Mark A. Odell

Jan 1, 1970
0
GAL,PAL,PLD, CPLD,FPGA, (what else...?)

GAL : Generic Logic Array

I thought this was: Gate Array Logic.
Can all these units can be programmable with VHDL ?

That's a language. As long as someone has a tool to convert VHDL source
code to the device's expected "bit" file then yes.
 
R

Roland Macho

Jan 1, 1970
0
GAL,PAL,PLD, CPLD,FPGA, (what else...?)

GAL : Generic Logic Array
PAL : Programmable Array Logic
PLD : Programmable Logic Device
CPLD : Complex Programmable Logic Device
FPGA : Field Programmable Gate Array

Can someone explain with comparison what is the difference between all these
GAL,PAL,PLD, CPLD,FPGA, (what else...?) logic units?

Can all these units can be programmable with VHDL ?

Hello,
As a long year digital expert I'll try to tell you the difference of all
these logic parts.
First: the content of all of them can be described by the language VHDL.
But this makes sense only with higher complexities, which big CPLDs and
FPGAs have.
PLDs, PALs and GALs are the lowest complexity of logic arrays (f.e.
22V10 -> 10 Flip-Flops + AND/OR-Logic).
CPLDs and FPGAs have more gates and Flip-Flops, where CPLDs have a more
fixed structure (predefined number of gates and FFs) , while FPGAs are
consisting sometimes of pure gates (ACTEL, Antifuse) and can be handled like
true gate arrays. FFs are built by gates then.
For the high complexities VHDL is the right tool to handle big designs.
But you should keep in mind, that the later layout of the FPGA-chip depends
on the design (how many IO-ports, number of FFs, number of gates, number of
logic blocks etc.).
The best way to learn about the digital designs is to use the partly free
tools and do a design by yourself.
All suppliers have nice kitparts and offer design software .

Have fun.

Regards,
Roland
 
G

Guest

Jan 1, 1970
0
Dear Roland,

Thank you for your clear and easy to understand summary.
The best way to learn about the digital designs is to use the partly free
tools and do a design by yourself.
Can you recomment a particular one to learn CPLD/FPGA and VHDL?
 
L

Leon Heller

Jan 1, 1970
0
Dear Roland,

Thank you for your clear and easy to understand summary.
Can you recomment a particular one to learn CPLD/FPGA and VHDL?

I have a simple CPLD design on my webs site that may be used with the free
Xilinx Webpack software.

Leon
 
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