HP 64751 User Manual page 127

Chapter 5: Configuring the Emulator
Selecting the Emulation Monitor
The starting address of the monitor block is set by answering the "Monitor's base
address?" question, and your response to the "Enable /DSACK interlocking on
monitor addresses?" question determines whether the dsi (/DSACK interlock)
memory attribute is added.
When you select a foreground monitor, the emulator automatically loads the default
program, resident in emulator firmware, into dual-ported emulation memory. The
foreground monitor is reloaded every time the emulator breaks into the monitor
state from the reset state.
Unlike the background monitor, the foreground monitor runs within the same
address space as the target program consuming a 4 Kbyte block of the 68340's
address range. The foreground monitor can run with target interrupts enabled (see
"Selecting the Interrupt Priority Level" below).
The emulator breaks into the foreground monitor by using the emulation
processor's background debug mode (BDM) except for single-stepping, which uses
the trace exception. The time spent in BDM is approximately 350 microseconds.
An exception stack frame of 7 to 13 words will be temporarily pushed onto the
user's master and/or interrupt stack(s) during monitor entry.
Selecting the Interrupt Priority Level
The default foreground monitor can be configured to run at a lowered interrupt
priority level to allow critical target system interrupts to be processed during
monitor execution.
At the point it is safe to lower the interrupt priority level, the foreground monitor
will set the interrupt priority mask to the value specified or the interrupt level that
was in effect before monitor entry, whichever is greater.
During background monitor operation, all target system interrupts, including level 7
non-maskable interrupts, are blocked.
Modifying this configuration item will reset the processor.
Selecting the Monitor's Base Address
Your response to the "Monitor's base address?" question defines the starting
address of the 4 Kbyte block of dual-ported emulation memory. This block of
memory is reserved for the foreground monitor. The address must reside on a
4 Kbyte boundary (in other words, an address ending in 000H) and must be
specified in hexadecimal. Also, the foreground monitor's base address must have
no function code specified.
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