Testing Memory Access With The Foreground Monitor - HP 64782 Series Manual

Chapter 4: Connecting the Emulator to a Target System
Installing Emulator Features
Keep-alive circuits that require a certain address to be accessed probably will fail
when you are using the foreground monitor. The keep-alive problem will most
likely show up immediately when using the foreground monitor. If the monitor is
interlocked, it will be affected immediately if a keep-alive circuit causes a bus
error. If a keep-alive circuit generates an interrupt or a reset, it should also be
immediately obvious. If reset is only temporarily asserted, it may not be so
obvious because the emulator will return to the monitor when it is released.
If you suspect a problem with a keep-alive circuit, try using the custom foreground
monitor. This monitor can be customized to take the required actions to satisfy a
keep-alive circuit. Look in the graphical interface manuals for information on
using the custom foreground monitor. Retry your reset into the monitor with the
customized foreground monitor.
If keep-alive circuits cannot be accommodated by using the available emulator
features, you may need to disable them for emulation.
Testing memory access with the foreground
monitor
Once the foreground monitor looks like it is running properly, you can use it to test
accesses to different ranges of memory in your target system. This may be an
easier way to diagnose problems than by running a program that accesses each
memory range. It is also easy to check accesses of different sizes using the monitor.
mo -ax -dl
m 0badad=12345678
When accesses to your target memory are not performed exactly right, the monitor
attempts to diagnose these problems and resolve them so the monitor program does
not malfunction. However, the monitor does not read back write cycles to check
the integrity of the data written. When testing memory accesses, check the data to
make sure it is correct.
M>m 0badad
00badad ffdf00ff
If your target memory does not respond to a bus cycle, the monitor will force
termination of the cycle and report this error message.
!ERROR 700! Target memory access failed
85