1		i	synthesize instructions events
2		b	synthesize branches events
3		c	synthesize branches events (calls only)
4		r	synthesize branches events (returns only)
5		x	synthesize transactions events
6		e	synthesize error events
7		d	create a debug log
8		g	synthesize a call chain (use with i or x)
9
10	The default is all events i.e. the same as --itrace=ibxe
11
12	In addition, the period (default 100000) for instructions events
13	can be specified in units of:
14
15		i	instructions
16		t	ticks
17		ms	milliseconds
18		us	microseconds
19		ns	nanoseconds (default)
20
21	Also the call chain size (default 16, max. 1024) for instructions or
22	transactions events can be specified.
23