HP MC68040 User Manual page 689

Entry into the foreground monitor can be traced by using the following trigger
specification. The interrupt acknowledge signal is not shown to the target system
and is also not shown to the analyzer unless background cycles are being traced.
tck -ub
tp c
tg stat=11xxxxxxxx1x111xy
t
b
Line addr,H 68040 Mnemonic
----- -------- ------------------------------------------
-2 00000008 $60FE0000 phy sprog long read
-1 0000000c $00000000 phy sprog long read
0 ffffffff $------FF mon int7 ack
1 00000200 $0000040B mmu twalk data long read
2 00000400 $0000060B mmu twalk data long read
3 0000063c $0000F01B mmu twalk data long read
4 0000f0ee $----007C phy sdata word write
5 0000f0ea $----0000 phy sdata word write
6 0000f0ec $0008---- phy sdata word write
7 00000200 $0000040B mmu twalk data long read
8 00000400 $0000060B mmu twalk data long read
9 00000600 $0000009F mmu twalk data long read
10 0000007c $000016C2 phy sdata long read
11 0000f0e8 $2700---- phy sdata word write
12 00000200 $0000040B
13 00000400 $0000060B
14 00000600 $0000101b
15 000016c0 $4E732F0D phy sprog long read
16 000016c4 $4BFAFB10 phy sprog long read
If you have problems trying to break into the monitor, the most likely causes are
that the stack pointers or vector base register do not point to valid memory. Any
exceptions during monitor entry will cause the break to fail. Access errors during
stacking or vector fetches are the most common causes of failures. The target
system can respond with a bus error, or if the MMU is running, the MMU can
signal an access error. The MMU will signal an error if a translation is not
available, if a bus error occurs during translation lookup, or if a write-protection
error occurs.
The break will also fail if accesses to the monitor cause an exception. This includes
bus errors and access errors signaled by the MMU. It is possible for the monitor to
execute correctly until the MMU is enabled, and then have problems. Keep in
mind that the monitor must be translated logical=physical and located in address
space that is not write-protected.
Chapter 18: Connecting the Emulator to a Target System
twalk prog long read
twalk prog long read
twalk prog long read
Installing Emulator Features
<- acknowledge
<- twalk stack
<- stack format
<- stack PC high
<-stack PC low
<- twalk vector
<- vector fetch
<- stack SR
<- twalk monitor
<- monitor
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