Chapter 4 Programmable Logic Devices: CPLDs with VHDL Design Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

PLD Design Flow Thousands of basic logic gates Advanced sequential functions Single package Not yet configured to perform a function Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

PLD Design Flow CAD to draw the schematic Schematic Capture to convert to binary file Program to alter PLD internal connections VHDL - Very High Speed Integrated Circuit Hardware Description Language –architecture body Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

PLD Design Flow See Figure 4-2 Define the problem Develop the equations Enter the design Simulate the input/output conditions Program the PLD Test the final programmed PLD Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Figure 4-2 Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

PLD Design Flow Implementing X=AB + B + C –Using 7400 series ICs –Using a PLD Altera Corporation tools –MAX+PLUS II (entry-intermediate level) –Quartus II (more advanced) –UP-1 or UP-2 Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

PLD Architecture SPLDs –most basic –least expensive –configurable logic gates –programmable interconnection points –may have memory flip-flops –typically 16 inputs and 8 outputs –product terms from AND gates Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

PLD Architecture PALs –programmable array logic –gives Sum-of-Products form –uses OR gate PLAs –programmable logic array –uses programmable OR gates Flip-flop memory section Data steering circuitry Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

PLD Architecture PAL16L8 is a typical PAL device –16 indicates 16 inputs –8 indicates 8 outputs –L means outputs are active LOW Refer to the data sheet for a logic diagram Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

PLD Architecture CPLDs –complex programmable logic devices –combine several PAL-type SPLDs into single package –non-volatile –repeatedly programmed Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

PLD Architecture FPGAs –field-programmable gate arrays –uses a look-up-table –more dense than CPLD –memory is volatile –see figure 4-11 Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Figure 4-11 Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Using PLDs to Solve Basic Logic Designs Block editor –connect pre-defined logic symbols VHDL editor –define the logic Compiler –language and symbol translation program Waveform Simulator –to check the logic operation Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Using PLDs to Solve Basic Logic Designs Using Quartus II CPLD software to implement a 2 input AND gate –See figure 4-13(a) for a screenshot of a block editor version –See figure 4-13(b) for a screenshot of a VHDL text version library declaration entity declaration architecture body Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Using PLDs to Solve Basic Logic Designs Using Quartus II CPLD software to implement a 2 input AND gate –Figure 4-13(c) is a screenshot of the waveform editor after simulation Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Figure 4-13(a) Figure 4-13(b) Figure 4-13(c) Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Tutorial for Using Altera’s Quartus II Design Software Build a solution to X=AB + CD –create a block design file –assign the file a name –specify a project name –draw logic circuits –add input and output pins –connect the symbols –assign a device to implement the design –save and compile to check for errors Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Tutorial for Using Altera’s Quartus II Design Software Test and simulate the solution to X=AB + CD –create a new vector waveform file –assign the same name as the design file –create node names for inputs and outputs –develop 4 input waveforms to cover all 16 possible inputs –compile and simulate to verify that output satisfies equation Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Tutorial for Using Altera’s Quartus II Design Software Programming the PLD using the Altera UP-2 or the RSR PLDT-2 programmer board –downloads logic design to actual PLD –the EPM7128S CPLD –configuring and connecting UP-2 programmer board –see figure 4-39 Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Figure 4-39 Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Tutorial for Using Altera’s Quartus II Design Software Programming the PLD using the Altera UP-2 or the RSR PLDT-2 programmer board –configuring and connecting PLDT-2 programmer board –see figure 4-40 Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Figure 4-40 Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Tutorial for Using Altera’s Quartus II Design Software Programming the PLD using the Altera UP-1 or the RSR PLDT-2 programmer board –connect switches and LED to CPLD pins –assign pin numbers in the boolean1.bdf file –connect wires to the input stimulus switches and output LED –download (program) the CPLD –test the downloaded design Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

CPLD Applications Follow the step by step process from section 4-4 to implement the following: –X=AB + AB –X=ABC –X=ABC + ABC Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Summary Programmable Logic Devices can be used to replace 7400-series and 4000-series ICs. They contain the equivalent of thousands of logic gates. Computer-Aided Design (CAD) tools are used to configure them to implement the desired logic. Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Summary The two most common methods of PLD design entry are graphic entry and VHDL entry. To use graphic entry the designer uses CAD tools to draw the logic that needs to be implemented. To use VHDL entry the designer uses a text editor to write program descriptions defining the logic to be implemented Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Summary PLD design software usually includes a logic simulator. This feature allows the user to simulate levels to be input to the PLD and shows the output simulation to those input conditions. Most PLDs are erasable and re-programmable. This allows the user to test many versions of their logic design without ever changing ICs. Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version

Summary Basically there are three types of PLDs: SPLDs, CPLDs and FPGAs. SPLDs consist of several multi-input AND gates feeding the inputs to OR gates and memory flip- flops. The CPLD consists of several interconnected SPLDs. The FPGA is the most dense form of PLD. It solves its logic using a look-up table to determine the desired output. Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. William Kleitz Digital Electronics with VHDL, Quartus® II Version