Changes between Version 31 and Version 32 of Other/Summer/2020/FPGAspectrum

Timestamp:

Jul 30, 2020, 12:09:35 AM (4 years ago)

Author:

rgd51

Comment:

—

Other/Summer/2020/FPGAspectrum

@@ -244 +244 @@
 }}}
 
+== Random Number Generation with LFSR ==
+{{{#!go
+\\ Jacob Morin
+
+// Call with either 1 or 3 command arguments:
+// First command argument: amount of loops
+// Second command argument: start
+// Third command argument: end
+package mainimport (
+    "fmt"
+    "os"
+    "strconv"
+)func lfsr3(sequence chan uint8, start int, end int, repititions int) {
+    for i := 0; i <= repititions; i++ {
+        //starting value
+        var seed uint16 = uint16(i)
+        //keeps track of the value at any given time
+        var lfsr uint16 = seed        //number of times it takes for the lfsr to revert to its start state
+        var period int = 0
+        //last bit of lfsr
+        var value uint16 = 0
+        //number of 0's in lfsr
+        var numZeros int = 0
+        //number of 1's in lfsr
+        var numOnes int = 0        stop := false
+        //until LFSR goes back to its start state (stop will become true)
+        for stop != true {
+            //increments count
+            period++            //shifts
+            lfsr ^= lfsr >> 7  //7 right
+            lfsr ^= lfsr << 9  //9 left
+            lfsr ^= lfsr >> 13 //13 right            if (period > start) && (period < end) {
+                //adds last bit to sequence
+                value = lfsr & 1
+                if value == 0 {
+                    numZeros++
+                    sequence <- 0
+                }
+                if value == 1 {
+                    numOnes++
+                    sequence <- 1
+                }
+            }            //if LFSR reaches startState, make stop true to exit the loop
+            if lfsr == seed {
+                stop = true
+            }
+        }    }}func main() {    //makes channel for the random number
+    sequence := make(chan uint8)    //command line
+    args := os.Args
+    len := len(args)    //first argument in command line determines how many times to loop
+    if len > 1 {
+        repititions, err := strconv.Atoi(args[1])
+        if err != nil {
+            fmt.Println("error")
+        }
+        // assumed values
+        start := 6000
+        end := 7000        // second argument in command line overrides start
+        // third argument in command line overrides end
+        if len > 3 {
+            y, err := strconv.Atoi(args[2])
+            if err != nil {
+                fmt.Println("error")
+            }
+            start = y            z, err := strconv.Atoi(args[3])
+            if err != nil {
+                fmt.Println("error")
+            }
+            end = z
+        }
+        //calls function
+        go lfsr3(sequence, start, end, repititions)        printSequence := ""
+        //Call lfsr3 'repitions' number of times
+        for i := 1; i <= repititions; i++ {
+            //number of values per sequences
+            for j := 0; j < 999; j++ {
+                //receives and prints value
+                value := <-sequence
+                printSequence += strconv.Itoa(int(value))
+            }            fmt.Println("At", i, "got random number:", printSequence, "\n")
+            printSequence = ""
+        }
+    }}
+}}}
+