how to count only adjacent(linked) 1's quantity in 7X7 matrix buffer using fpga?

I assume the code you have posted is incomplete, because it has syntax errors.

Your current code is somply the sum of all bits of an array in parrallel. I assume ultimately your input will be an image? this would be streaming only 1 pixel per clock cycle. To check adjacent 1s you're going to need an algorithm to found out whether one is adjacent to another.

And to explain:

In a processor - in a CPU

Thresholding - taking an image and transforming the raw data by setting specific values to 0 (those that fail to meet some threshold criteria, eg. the luminance value is below a given value)

300 Hz refresh - the frame rate of the image - the pixel rate was 27Mhz.