trapchk#

Purpose#

Tests the value of the trap flag.

Format#

y = trapchk(m)#

Parameters:: m (scalar) – mask value
Returns:: y (scalar) – the result of the bitwise logical AND of the trap flag and the mask value.

Remarks#

To check the various bits in the trap flag, add the decimal values for the bits you wish to check according to the chart below and pass the sum in as the argument to the trapchk() function:

bit	decimal value
0	1
1	2
2	4
3	8
4	16
5	32
6	64
7	128
8	256
9	512
10	1024
11	2048
12	4096
13	8192
14	16384
15	32768

If you want to test if either bit 0 or bit 8 is set, then pass an argument of 1+256 or 257 to trapchk(). The following table demonstrates values that will be returned for:

y = trapchk(257);

	0	1	value of bit 0 in trap flag
0	0	1
1	256	257
value of bit 8 in trap flag

GAUSS functions that test the trap flag currently test only bits 0 and 1.