Conversion to YAML

content/post/bit-magic/index.md

@@ -4,6 +4,7 @@ subtitle: "Tips and trick for embedded C/C++"
 summary: "Tips and trick for embedded C/C++"
 date: 2020-06-13T19:01:19+02:00
 highlight: true
+math: true
 ---
 
 # Set a bit
@@ -53,12 +54,21 @@ output = input << 3; // Multiply by 8
 output = (0b1 << X) -1;
 ```
 
+# Minimum required bits
+$$bits = { log(number) \over log(2) }$$
+Since you can not use fractions of a bit the number should be rounded up.
+
 # Miscellaneous
 ```c
 // Check if number is ODD
 if( (num & 1) == 1) {};
 // Flip signed integer
 num = ~num + 1;
-// Power of two
+// Is an integer a power of two?
 num > 0 && (num & (num - 1)) == 0;
+//Clear all bits from 0 to N
+mask = ~((1 << n+1 ) - 1);
+x &= mask;
+
+
 ```