Show/Suppress; Code Synchronization; Idt Description - HP E2444A User Manual

Show/Suppress

Code
Synchronization

IDT Description

HP E2444A
80386DX/DXL Preprocessor Interface
The Suppress/Show settings determine whether the various
microprocessor operations are shown or suppressed on the logic
analyzer display. Figure 2-11 shows the microprocessor operations
which have this option. The settings for the various operations do not
affect the data which is stored by the logic analyzer, they only affect
whether that data is displayed or not. The same data can be examined
with different settings, for different analysis requirements.
This function allows faster analysis in two ways. First, unneeded
information can be filtered out of the display. Figure 2-11 shows the
settings to suppress unexecuted prefetches. Figure 2-7 (page 2-9)
shows a listing with the unexecuted prefetches suppressed, so that only
executed instructions are displayed. A comparison of figures 2-7 and
2-6 (page 2-8) shows the difference in the listing display.
Second, particular operations can be isolated by suppressing all other
operations. For example, I/O accesses can be shown, with all other
operations suppressed, allowing quick analysis of I/O accesses.
The Code Synchronization enables the inverse assembler to
resynchronize with the microprocessor code. In some cases the
prefetch marking algorithm in the inverse assembler may lose
synchronization, and unused prefetches or executed instructions may
be incorrectly marked. If any of the Code Reads are suppressed, this
could cause some executed instructions to be missing from the display.
To resynchronize the inverse assembler, use the procedure on page
2-11.
The IDT Description settings include Mode, IDT Start, and IDT Size.
Mode can be Protected, Real, or Virtual. IDT Start refers to the
starting address of the Interrupt Descriptor Table, and IDT Size refers
to the size of the table. Set these functions to match the target system
settings.
In most cases, the inverse assembler can automatically determine the
target system settings, and will operate properly regardless of the
settings entered. The inverse assembler uses the information from
these settings only in cases of uncertainty. If you suspect that the
inverse assembler is disassembling improperly, check that these settings
match your target system.
Analyzing the Intel 80386DX/DXL
2-19