Intel 64 and IA-32 Architectures Software Developers Manual Volume 3B, System Programming Guide Part 2

Table Of Contents
Vol. 3 18-3
DEBUGGING AND PERFORMANCE MONITORING
Whether the breakpoint condition was present when the debug exception was
generated.
The following paragraphs describe the functions of flags and fields in the debug
registers.
Figure 18-1. Debug Registers
31
24
23
22
21 20 19 16
15
13
14 12
11
87
0
DR7
L
Reserved
0
123456
910
1718
252627282930
G
0
L
1
L
2
L
3
G
3
L
E
G
E
G
2
G
1
0 0
G
D
R/W
0
LEN
0
R/W
1
LEN
1
R/W
2
LEN
2
R/W
3
LEN
3
31
16
15
13
14 12 11
8
7
0
DR6
B
0
123456
910
B
1
B
2
B
3
0111111111
B
D
B
S
B
T
31
0
DR5
31
0
DR4
31
0
DR3
Breakpoint 3 Linear Address
31
0
DR2Breakpoint 2 Linear Address
31
0
DR1
Breakpoint 1 Linear Address
31
0
DR0Breakpoint 0 Linear Address
001
Reserved (set to 1)