There are three functions that can be used in routing blocks to operate with flags.
This function sets the value of the flag given as parameter to 1 (true). The value of the parameter must be an integer between 0 and 31.
Example 3. setflag(15) -- set the 15th flag
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ |0|0|0|0|0|0|0|0| |0|0|0|0|0|0|0|1| |0|0|0|0|0|0|0|0| |0|0|0|0|0|0|0|0| +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
If the value of the flag was already set, the operation has no other effect, the flag remains set to 1.
The function returns always true.
This function resets the value of the flag given as parameter to 0 (false). The value of the parameter must be an integer between 0 and 31, too.
Example 4. resetflag(15) -- reset the 15th flag
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ |0|0|0|0|0|0|0|0| |0|0|0|0|0|0|0|0| |0|0|0|0|0|0|0|0| |0|0|0|0|0|0|0|0| +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
If the value of the flag was already 0, the operation has no other effect, the flag remains set to 0.
The function returns always true.
This function tests the value of the flag given as parameter. The value of the parameter must be an integer between 0 and 31, too.
The function returns true, if the value of the flag is 1, and false, if the value of the flag is 0.
Example 5. isflagset(15)
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|0|0|0|0|0|0|0|0| |0|0|0|0|0|0|0|1| |0|0|0|0|0|0|0|0| |0|0|0|0|0|0|0|0|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
# when the flags' bit map is as above
if(isflagset(15))
{
# this branch is executed
} else {
# not in this case
};