CCS/LAUNCHXL-F28379D: 2D Lookup Table

Kevin,

Perhaps you can create 2 1D arrays X[N] and Y[N] that map to each other as you mention i.e. X[m] maps to Y[m]? I presume you have some external input or variable, k, that you will map to X, and depending on where it lands, you will pick the corresponding value in Y.

In other words, something like:

while(k < X[i]){

i++;}

value = Y[i];

We have dealt with conditional sized loops like this before in a similar context - LUT search loops through sorted arrays. In order to keep cycles down, you should pay close attention to the type of the loop search index i. Typically it should be declared as a signed, so as to allow the compiler to generate the efficient indexed addressing mode instructions. For unsigned, the C standard needs to support overflow, so typically the compiler will not generate those.

Thanks,

Sira