Questions about data storage and RAM resource usage in CompactRIO

[2528642245@qq.com]

First of all my device is a CRIO-9043.

I want to use one dimensional lookup table for interpolation in FPGA.vi, I am using U16 data type and one lookup table can store 40960 data and I need to store 7 million data. Currently I have inserted only 16 tables and the RAM resources are not enough. My compilation tells me that one lookup table takes up 19 RAM resources (my device has a total of 325 RAM resources).

But on the lookup table it shows that one table uses only 80KB of storage, while on the official website the CRIO-9043 has a RAM size of 2G!

I don't know how to solve this problem. Attached is my program, sorry it's only in Chinese!

[GerdW]

Hi 252,

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2528642245@qq.com wrote:

But on the lookup table it shows that one table uses only 80KB of storage, while on the official website the CRIO-9043 has a RAM size of 2G!

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Don't get confused about RAM (accessable by the CPU) and block memory (accessable by the FPGA)!

Your FPGA cannot access host RAM this easily…

Btw. did you read the datasheet&specs of your cRIO?

The FPGA can only handle 11,700kbits of block RAM! (= 1462.5 kByte ~= 18 tables of 80kB for optimal usage…)

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2528642245@qq.com wrote:

I want to use one dimensional lookup table for interpolation in FPGA.vi, I am using U16 data type and one lookup table can store 40960 data and I need to store 7 million data. Currently I have inserted only 16 tables and the RAM resources are not enough.

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Do you want to use "one lookup table"?

Do you want to use more than one table? How many?

Why do you need "7 million data" in your FPGA algorithm?

Please explain what your goal is and what your requirements are!