36-54 Vol. 3C
INTEL® PROCESSOR TRACE
36.4.2.16 Overflow (OVF) Packet
36.4.2.17 Packet Stream Boundary (PSB) Packet
Table 36-35. OVF Packet Definition
Name
Overflow (OVF) Packet
Packet Format
Dependencies
TriggerEn
Generation
Scenario
On resolution of internal buffer overflow
Description
OVF simply indicates to the decoder that an internal buffer overflow occurred, and packets were likely lost. If
BranchEN= 1, OVF is followed by a FUP or TIP.PGE which will provide the IP at which packet generation resumes. See
Application
When an OVF packet is encountered, the decoder should skip to the IP given in the subsequent FUP or TIP.PGE. The
cycle counter for the CYC packet will be reset at the time the OVF packet is sent.
Software should reset its call stack depth on overflow, since no RET compression is allowed across an overflow. Sim-
ilarly, any IP compression that follows the OVF is guaranteed to use as a reference LastIP the IP payload of an IP
packet that preceded the overflow.
Table 36-36. PSB Packet Definition
Name
Packet Stream Boundary (PSB) Packet
Packet Format
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
1
0
1
1
1
1
1
0
0
1
1
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
1
0
1
1
0
0
0
0
0
1
0
2
0
0
0
0
0
0
1
0
3
1
0
0
0
0
0
1
0
4
0
0
0
0
0
0
1
0
5
1
0
0
0
0
0
1
0
6
0
0
0
0
0
0
1
0
7
1
0
0
0
0
0
1
0
8
0
0
0
0
0
0
1
0
9
1
0
0
0
0
0
1
0
10
0
0
0
0
0
0
1
0
11
1
0
0
0
0
0
1
0
12
0
0
0
0
0
0
1
0
13
1
0
0
0
0
0
1
0
14
0
0
0
0
0
0
1
0
15
1
0
0
0
0
0
1
0