Program Trace Overflow Error Messages - STMicroelectronics SPC572L series Reference Manual

e200z215An3 Nexus 3 Module
(1–32 bits)
Branch History
Max length = 56 bits; Min length = 18 bits
(1–8 bits)
Sequence Count
66.12.5.1 Program Correlation message generation for PID updates
When a (potentially) new value is established in the selected process ID register via a
mtspr PID0/NPIDR, a Program Correlation message is generated containing the
information regarding the new process ID value. This PCM also contains the current history
and instruction count. The message is provided so that address translation information can
be processed by the development tool in the proper program flow. The mtspr PID0/NPIDR
is included in the instruction count information. Note that Ownership Trace Messages (other
than the periodic OTM) are redundant with the information provided, and may be disabled to
avoid unnecessary message bandwidth or collisions.
66.12.6

Program Trace Overflow Error messages

an Error Message occurs when a new message cannot be queued due to the message
queue being full. The FIFO will discard incoming messages until it has completely emptied
the queue. Once emptied, an Error Message will be queued. The error encoding will indicate
which type(s) of messages attempted to be queued while the FIFO was being emptied.
66.12.7 Program Trace Synchronization messages
By default, program trace messages will perform XOR compression on the branch target
address to produce the address field for the message. This compression is consistent with
the specification in IEEE-ISTO 5001.
Under some conditions an uncompressed address is sent to provide development tools with
a baseline reference address. A Program Trace Synchronization message is messaged via
1956/2058
Figure 1167. Program Correlation message formats
(1–8 bits)
(2 bits)
Sequence Count
CDF
(2 bits) (4 bits)
*
CDF EVCODE
(1–32 bits)
PID
(CDATA 2)
Max length = 88 bits; Min length = 20 bits
DocID027809 Rev 4
(4 bits)
(4 bits)
*
EVCODE
Src. Proc.
*
CDF= 01,
EVCODE = Any but 0101, 1100
(4 bits)
TCODE (100001)
Src. Proc.
(1–32 bits)
Branch History
(CDATA 1)
(6 bits)
TCODE (100001)
(6 bits)
*
CDF=10
**
- EVCODE = 0101
RM0400