HI all!!!

Finally I found it's cause ... Ha!

Thanks everybody who try to help me but don't know how to answer. :)

Let me commit my experinces to 8052 's knowledge database .

The problem is

Default memory uC/OSII is large model and I've only 32Kbytes of XRAM.
The default top of reentrant stack for large memory model in startup.a51 is 0xffff .
It's occur when the reentrant stack doesn't meet their exact data on real hardware .


There 're 2 ways handling.

1. you 've to select
set the default top of reentrant stack to 0x7fff in large memory model or
2. you've to change to compact memory model and reserve 0x0000 to 0x0100
like

XSEG AT 0000H
?REENTSTK: ds 256

have fun!