Texas Instruments 74LS Counter Shift Registers are available at Mouser Electronics. Mouser offers inventory, pricing, & datasheets for Texas Instruments . 74LS, 74LS Datasheet, 74LS 8-bit Serial Shift Register Datasheet, buy 74LS Texas Instruments 74LS Logic – Shift Registers parts available at DigiKey.
|Published (Last):||19 January 2014|
|PDF File Size:||20.73 Mb|
|ePub File Size:||15.55 Mb|
|Price:||Free* [*Free Regsitration Required]|
This file contains not only the stimulus, but also the expected responses. The gate-level simulation test bench compares the expected responses with actual responses from the circuit and 74ls615 error messages if they do not match. However, for a more complicated circuit, the expected outputs should be generated and used for functional simulation.
These setup files are different from those of the CMC tutorials as a generic technology has been used for the example. This can be done with a C program or with a Perl script.
Since this is a very simple circuit, there is no expected output included in the test vector generation program. The implementation is very simple and a novice VHDL designer should be able to 74os165. In general, physical testing takes much less time than simulation in Synopsys so a more exhaustive set of test vectors can be used for the physical test.
Each line of the file consists of one vector of stimulus data that the VHDL test bench reads. The test 74ls1665 uses a clock to output the stimulus data in a periodic manner.
Both test benches use a similar approach which imports the stimulus test vectors in a file and the simulation results are written to an output file. For the 74LS, the Perl script topcf. 74s165
To perform functional and gate-level simulations, the VHDL test benches lstb. To perform functional simulation, synthesis, and gate-level simulation with these files, the following Synopsys setup files should be used: The functional test vectors are generated with a simple C program lstv. Synopsys is used to synthesize the VHDL code to a gate-level circuit using the Synopsys’ Class library as the target library.
All source files are included so that the reader can download the files and try to setup the test on his or her own.
The rest of this section describes the steps on Figure 5 for the 74LS The output file from the Test Fixturing Software can be used to make the jumper connections on the test 74,s165 and to connect the timing and pattern pods from the VXI mainframe to the test head.
After gate-level simulation, the design can be exported to Cadence to finish the rest of the design flow as described in the Design Flow section.
The expected outputs are actually generated by the functional simulation. Since the CMC digital tutorial contains a step by step procedure of how to use the Test Fixturing Software, a description will not be given here.
To be able to use the test vectors for 74,s165 testing, the test vector file needs to be converted to HP PCF format. For this example, the gate-level simulation output file is to be used for the physical test.
The gate-level simulation uses the output file from the functional simulation as input file. The C program prints a set of test vectors to stdout which can be redirected to a text file.