Hello, my name is Shiwashiwa.
In the last issue, I wrote about how to generate memory IPs and memory presets.
This time, I would like to explain about the points to keep in mind when using memory presets and how to save and recall them.
1. points to note about memory presets
A senior said to me, "Let's try to generate a memory IP with the same conditions as our customer's as an exercise to create a memory IP.
So, I checked the FPGA and memory, then selected the corresponding preset and generated the memory IP.
Senior: "The value is wrong."
Shiwashiwa: "I used the preset."
Senior: "The preset is set to the value at the maximum operating frequency of the memory to be used, so you need to change the value according to the actual frequency to be used."
Shiwashiwa "......!"
The preset values are the parameters at the maximum operating frequency for the FPGA and memory used. If you do not want to operate at the maximum operating frequency, you need to change the parameters.
2. Calculation of memory parameters
In this case, we generated a memory IP with the same conditions as the customer, so we used Cyclone® V and JEDEC DDR3-1066E 1GB x 8 memory,
Set Hard IP, Speed Grade: 6, Operating Frequency: 350 MHz, and Clock Rate: Full.
Read the data sheet of the memory to be used and enter the values.
The values of Memory Timing, Memory Parameters, and Board Settings need to be changed. As an example, let us calculate the value of the parameter tRTP (Read To Precharge time).
The calculation method is as follows. If the operating frequency is 350 MHz, the value of tRTP is 11.4.
For detailed parameter settings and explanations, please refer to the following
Click "Documentation" in the upper right corner of the parameter setting screen.
How to set memory parameters for DDR3 UniPHY IP.
Shiwashiwa: "It's a hassle to do this every time I think of doing it... It's really hard to generate memory IPs, isn't it?"
Senior: "You can save the parameters you set as a preset."
Shiwashiwa"......!"
3. saving and recalling presets
Memory presets can be saved and used anytime once the parameters have been set.
In Quartus Prime, select Tools ⇒ IP Catalog ⇒ Memory IP ⇒ Generation Folder and HDL Language to display the memory parameter input screen.
After selecting a preset, calculate the parameters and change the operating frequency and clock rate values.
When the parameters have been changed, press "New" at the bottom right of the screen to move to the Preset Save screen.
Here you can select the name and description of the preset, the directory to save the preset, and the items of the preset you wish to save.
Pressing "Save" will save the preset with the set values.
In this case, we will save the preset with the name "Preset 1".
In the list of presets, you can see that "Preset 1" has been added to the list.
Select "Preset 1" and press "Apply" to apply the saved data.
Now that we know how to save and recall customized memory presets, we would like to make use of this information to efficiently generate memory IPs and to check the operation when switching each option on and off.
4. Summary
- Preset values are entered as parameter values at the maximum operating frequency for the FPGA and memory to be used.
- User-set parameters can be easily saved and recalled as presets.
5. Extra
Customized memory presets are saved in the directory and name set in the preset generation screen, so by copying this file, you can utilize the preset information in other projects.
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