參數(shù)資料
型號: EPXA4
廠商: Altera Corporation
英文描述: Excalibur Devices
中文描述: 神劍設備
文件頁數(shù): 19/34頁
文件大?。?/td> 277K
代理商: EPXA4
Altera Corporation
19
Errata Sheet - Appendix A
A.2.3
Instruction displayed before and after overflow—Category 2
Description
When the FIFO overflows, the last instruction to be traced immediately
before overflow may be repeated on recovery from overflow.
Conditions
The instruction must be executing when the overflow occurs and remain
so until trace is re-enabled following overflow.
This generally only arises
if a large number of wait states occur. Consequently it should only occur
in cached systems during a cache miss, or when using a very slow
memory system.
Since the ETM
FIFOFULL
signal attempts to preemptively insert
processor wait states to prevent the FIFO from overflowing, having
FIFOFULL enabled can also increase the occurrence of this problem.
Implications
It can appear that an instruction is executed twice when it was only
executed once.
Workaround for tools vendors
The development tools should be modified to discard the instruction
before the overflow, only displaying the instruction after overflow when
the addresses of the instructions before and after overflow match.
Occasionally this would cause an instruction to be discarded
unnecessarily, but a much larger number of instructions would already
have been discarded due to the overflow.
It is important that the instruction before overflow is the one to be
discarded, and not the one following overflow recovery, in case the
erratum is falsely detected. If trace is turned off during overflow
(TraceEnable goes LOW), then enabled again (TraceEnable goes HIGH)
some time after overflow recovery, the first instruction to be traced
following overflow may be significant and must be traced.
Implications of workaround
An extra instruction will occasionally be lost during an overflow
occurring in a loop. This will not be detectable by the user.
相關PDF資料
PDF描述
EPZ3001G Power Choke
EPZ3003G Power Choke
EPZ3006G Power Choke
EPZ3011G Power Choke
EPZ3011G-LF Power Choke
相關代理商/技術參數(shù)
參數(shù)描述
EPXA4F1020C1 制造商:Rochester Electronics LLC 功能描述: 制造商:Altera Corporation 功能描述:IC EXCALIBUR ARM 1020FBGA
EPXA4F1020C1ES 制造商:Altera Corporation 功能描述:IC EXCALIBUR ARM 1020FBGA
EPXA4F1020C2 制造商:Rochester Electronics LLC 功能描述: 制造商:Altera Corporation 功能描述:IC EXCALIBUR ARM 1020FBGA
EPXA4F1020C2ES 制造商:Altera Corporation 功能描述:IC EXCALIBUR ARM 1020FBGA
EPXA4F1020C3 制造商:Altera Corporation 功能描述:IC EXCALIBUR ARM 1020FBGA