How to see content of look up table - fpga

Imagine we have a simple code for fpga, I want to know if there is any way to watch content of specific lookUp table after synthesis, actually that data that will be written in SRAM
module test8(a,b,c
);
input a ;
input b ;
output c;
assign c = a&b;
endmodule
Simple AND gate

The possibility depends on the FPGA vendors tool.
Some tools has a GUI floor-plan view where the used LUTs can be found, and these LUTs can then have associated code attached for the memory contents of the LUT. In Altera Queatus Chip Planner it may look like:
Another option is to generate a netlist of the complete design, usually writable from the FPGA tool, and this netlist will then contain the LUTs together with code for the LUT contents. In Altera Quartus generated Verilog netlist it may look like:
...
// Location: LABCELL_X10_Y34_N0
cyclonev_lcell_comb \c~0 (
// Equation(s):
// \c~0_combout = ( \a~input0 & ( \b~input0 ) )
.dataa(gnd),
.datab(gnd),
.datac(!\b~input0 ),
.datad(gnd),
.datae(gnd),
.dataf(!\a~input0 ),
.datag(gnd),
.cin(gnd),
.sharein(gnd),
.combout(\c~0_combout ),
.sumout(),
.cout(),
.shareout());
// synopsys translate_off
defparam \c~0 .extended_lut = "off";
defparam \c~0 .lut_mask = 64'h000000000F0F0F0F;
defparam \c~0 .shared_arith = "off";
// synopsys translate_on
...
Note that the GUI view shows that the AND gate is not implemented using just a single simple LUT, since the tools has the freedom to implement it as it seems fit, as long as any timing and other requirements are observed.
But in the end, the specific implementation and considerations about LUT coding is usually ignored by the designer... except in special debugging cases.

I found vivado GUI for this Lookuptable

Related

How to inject a zero-noise signal compact binary coalescence signal

Is it possible to inject a signal by itself with no coloured Gaussian noise?
Question asked by Arunava Mukherjee via email
Yes. There are two easy ways to do this.
1) Use the existing helper functions
When generating an interferometer object, bilby provides several helper routines denoted by bilby.gw.detector.get_interferometer_with.... In this case, you'll want to use this function (I've truncated the doctring)
bilby.gw.detector.get_interferometer_with_fake_noise_and_injection(
name, injection_parameters, injection_polarizations=None,
waveform_generator=None, sampling_frequency=4096, duration=4,
start_time=None, outdir='outdir', label=None, plot=True, save=True,
zero_noise=False)
Docstring:
Helper function to obtain an Interferometer instance with appropriate
power spectral density and data, given an center_time.
Note: by default this generates an Interferometer with a power spectral
density based on advanced LIGO.
Parameters
----------
name: str
Detector name, e.g., 'H1'.
...
zero_noise: bool
If true, set noise to zero.
So you just pass the flag in and it will create an interferometer with just the injection signal (you'll then need to make one for each interferometer you want in the list of interferometers passed in to the likelihood.
2) Use the low level set strain data methods
Alternatively, you may instead wish to use the low level methods themselves. As a general rule of thumb, you can always look at the source code for the generic helper functions to figure out how this should be done. Here, we create a H1 interferometer set the strain data with zero noise and inject a signal:
interferometer = get_empty_interferometer("H1")
interferometer.power_spectral_density = PowerSpectralDensity.from_aligo()
interferometer.set_strain_data_from_zero_noise(
sampling_frequency=sampling_frequency, duration=duration,
start_time=start_time)
injection_polarizations = interferometer.inject_signal(
parameters=injection_parameters,
waveform_generator=waveform_generator)
Information correct as of v.0.3.5

optional vertexbufferobjects in directx11

I have some models (geometries) which have some vertexinformation. For example position, normal, color, texcoord each of this information has its own vertexbuffer. But some of these models have texture coordinates some not...
To manage these differences I wrote a vertexshader which is checking, if the flag inside the constantbuffer "hasTextureCoordinates" is == 1. And if so it uses the texcoord parameter or not.
But Directx does not realy like this workaround and prints out:
D3D11 INFO: ID3D11DeviceContext::Draw: Element [3] in the current Input Layout's declaration references input slot 3, but there is no Buffer bound to this slot. This is OK, as reads from an empty slot are defined to return 0. It is also possible the developer knows the data will not be used anyway. This is only a problem if the developer actually intended to bind an input Buffer here. [ EXECUTION INFO #348: DEVICE_DRAW_VERTEX_BUFFER_NOT_SET]
I'm not sure if every hardware handles this correctly, also it's not nice to see inside the output this "warnings" every frame...
I know i could write two shaders, one with and one without texcoods, but the problem is that this is not the only maybe missing parameter... some has color other not, some has color and texturecoordinates and so on. And to write a shader for each combination of vertexbuffer inputs is extremly redundant. this is extremly bad, because if we change one shader, we have to change all other too. There is also the possibility of put parts of the shader to different files and include them, but it's confusing.
Is there a way to say directx that the specific vertexbuffer is optional?
Or does someone knows a better solution for this problem?
You can suppress this specific message programmatically. As it's an INFO rather than an ERROR or CORRUPTION message, it's safe to ignore.
#include <wrl/client.h>
using Microsoft::WRL::ComPtr;
ComPtr<ID3D11Debug> d3dDebug;
if ( SUCCEEDED( device.As(&d3dDebug) ) )
{
ComPtr<ID3D11InfoQueue> d3dInfoQueue;
if ( SUCCEEDED( d3dDebug.As(&d3dInfoQueue) ) )
{
#ifdef _DEBUG
d3dInfoQueue->SetBreakOnSeverity( D3D11_MESSAGE_SEVERITY_CORRUPTION, true );
d3dInfoQueue->SetBreakOnSeverity( D3D11_MESSAGE_SEVERITY_ERROR, true );
#endif
D3D11_MESSAGE_ID hide[] =
{
D3D11_MESSAGE_ID_SETPRIVATEDATA_CHANGINGPARAMS,
D3D11_MESSAGE_ID_DEVICE_DRAW_VERTEX_BUFFER_NOT_SET, // <--- Your message here!
// Add more message IDs here as needed
};
D3D11_INFO_QUEUE_FILTER filter = {};
filter.DenyList.NumIDs = _countof(hide);
filter.DenyList.pIDList = hide;
d3dInfoQueue->AddStorageFilterEntries( &filter );
}
}
In addition to suppressing 'noise' messages, in debug builds this also causes the debug layer to generate a break-point if you do hit a ERROR or CORRUPTION message as those really need to be fixed.
See Direct3D SDK Debug Layer Tricks
Note I'm using ComPtr here to simplify the QueryInterface chain, and I assume you are keeping your device as a ComPtr<ID3D11Device> device as I do in in Anatomy of Direct3D 11 Create Device
I also assume you are using VS 2013 or later so that D3D11_INFO_QUEUE_FILTER filter = {}; is sufficient to zero-fill the structure.

Write data to sdcard zedboard

I want to write data to zedboard's sdcard. I am able to write data to DRAM. Now I want to read DRAM's data and write it Sdcard. I have followed this (http://elm-chan.org/fsw/ff/00index_e.html) but it does not fulfill my requirement. I am not able to find any tutorial any example etc for this.
Please any tutorial link or any example. Thanks.
If you're using Vivado SDK, which I assume you are, it is really straightforward to use the SD Card.
To include the Fat File System, inside Xilinx SDK, open your Board Support Package (system.mss file) an select Modify this BSP's Settings. Under Overview, you can select xilffs.
Next, you must write the software to access the SD Card. This library offers a wide variety of functions. You can either look at here_1, in here_2 or in here_3. In this second reference is provided a wide variety of complex functions.
Aside from this, in order to use the SD Card, what you should basically do is written below. Note that this is just an overview, and you should refer to the references I gave you.
# Flush the cache
Xil_DCacheFlush();
Xil_DCacheDisable();
# Initialize the SD Card
f_mount(0, 0);
f_mount(0, <FATFS *>)
# Open a file using f_open
# Read and Write Operations
# Either use f_write or f_read
# Close your file with f_close
# Unmount the SD with f_mount(0,0)
Note that experience teaches me that you need to write to the file in blocks that are multiples of the block size of the file system, which for the FAT files syste, is typically 512 bytes. Writing less that 512 bytes and closing the file will make it zero bytes in length.
In new version of Xilffs (Fatfs) lib syntax is little changed.
New syntax is:
static FATFS FS_instance; // File System instance
const char *path = "0:/"; // string pointer to the logical drive number
static FIL file1; // File instance
FRESULT result; // FRESULT variable
static char fileName[24] = "FIL"; // name of the log
result = f_mount(&FS_instance, path, 0); //f_mount
result = f_open(&file1, (char *)fileName, FA_OPEN_ALWAYS | FA_WRITE); //f_open
May be this can help you.

VHDL Verilog Integer Arrays Ports

I am working on a project for the FPGA implementation of the Breakout Game. In this game, we have to break the bricks using a ball and a paddle. Some bricks may break on multiple contacts with the ball. For this, I am using an integer array to represent the number of hits required to break a particular brick. eg (2,0,1,2) represents a brickk which needs 2 hits to be broken followed by a broken brick followed by a brick which needs a single hit to be broken et al.
Also, I have done all my coding in VHDL but in order to output the results onto the VGA screen, I am using Verilog.
In VHDL, I have declared a type for an integer array in a package as follows:
package mytypes_pkg is
type int_array is array (0 to 39) of integer;
end mytypes_pkg;
then in my ball motion controlling file, I have imported work.mytypes_pkg.all and then have:
brickout:out int_array;
which contains the current state of all the bricks in the game. This array has to be passed to my Verilog file where all the VGA Display generation has to take place. There, I tried
input [39:0] bricki;
but it gives me the error
"Different types for port 'brickout' on entity and component for 'mainc'"
How can I rectify this error and do what I want to do? Is there some way of telling Verilog that bricki is also of type int_array? And do I need to import work.mytypes_pkg.all in Verilog too?
In SystemVerilog you can use typedef to define your own types, e.g.
typedef int [N-1:0] mytype;
and this way build exactly what you want. Define your types in a package and then import it:
import pkg_keccak::mytype;
...
mytype int_table;

Displaying Two Different Variables On The 7 segment LED Display with the Help Of A Switch - VHDL and FPGA

I have been trying to display two different variables on the 7 segment led display on a spartan 3 fpga using VHDL language. This is for my final year project at uni and I'm really struggling. Can someone pleeeeeaaasssseee help? :(
Switch is a C reserved word. For VHDL you'll want to use case instead.
Here is the code for you:
if (Swtich_1 = '1') then
Seven_Seg <= Date_Time;
else
Seven_seg <= Temperature;
end if;
that is all you need :)
There are a few things you have to be careful about
Make sure you denounce the switch and it is clean
Make a simple seven segment converter to handle the data (simple case statement should do or a proces than you can find searching the net).
Hope it helps....

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