The 80386Dx Inverse Assemblers - HP 10314D User Manual

The 80386DX
Inverse
Assemblers
Note " '
The 80386DX inverse assemblers have been designed to support the
80386DX microprocessor with or without coprocessors. The following
paragraphs explain the operation of the inverse assemblers and the
results you can expect in certain conditions.
The 80386DX microprocessor can fetch instructions up to 4 bytes (32
bits) wide in a single bus cycle. However, the microprocessor does not
indicate externally which of the bytes fetched
is
the first byte of a code
fetch. You must "point" to the first byte of an instruction fetch. Once
synchronized, the inverse assembler will disassemble from this state
through the end of the screen.
In addition, the 80386DX microprocessor can execute two types of
object code. The 80386DX can execute the 80386DX instruction set
(32-bit), and it can also execute object code from Intel's 16-bit
microprocessor family, including software designed for the Intel 8086
and the Intel 80286. The user must tell the logic analyzer what "size" of
code
is
being executed by the microprocessor.
Size, as used here, has no relationship to the physical size of the
microprocessor's data bus. In this reference, size
is
used to indicate
whether the code being executed
was
originally designed to run on
Intel's 16-bit or 32-bit microprocessors.
Analyzing the Intel 80386DX
2-8
HP 103140
80386DX Preprocessor Interface