Tektronix Socket 7 TMS109A, Instruction Manual

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Acquiring and Viewing Disassembled Data
TMS 109A Socket 7 Microprocessor Support
2–15
The Software display format shows only the first fetch of executed instructions.
Flushed cycles and extensions are not shown, even though they are part of the
executed instruction. Read extensions will be used to disassemble the instruction,
but will not be displayed as a separate cycle in the Software display format. Data
reads and writes are not displayed (see Figure 2–8 on page 2–22).
Out-of-order fetches are shown in the order the fetches are executed. An asterisk
indicates an out-of-order fetch. The sample number of the out-of-order fetch will
not be displayed if the previously executed instruction has a higher sample
number. The sample number of the out-of-order fetch will be displayed if the
previously executed instruction has a smaller sample number.
Since you cannot place the cursor on an instruction without a sample number,
you will not be able to scroll to some out-of-order fetch instructions. To scroll to
these instructions, you will have to switch to the Hardware display format. You
also cannot mark an out-of-order fetch in software mode; you must switch to
hardware mode.
The Control Flow display format shows only the first fetch of instructions that
change the flow of control.
Instructions that generate a change in the flow of control in the Socket 7
microprocessor are as follows:
CALL IRET RET
INT JMP RSM
Instructions that might generate a change in the flow of control in the Socket 7
microprocessor are as follows:
BOUND JL/JNGE JNP/JPO
DIV JLE/JNG JNS
IDIV JNB/JAE/JNC JO
INTO JNBE/JA JP/JPE
JB/JNAE/JC JNE/JNZ JS
JBE/JNA JNL/JGE LOOP
JCXZ/JECXZ JNLE/JG LOOPNZ/LOOPNE
JE/JZ JNO LOOPZ/LOOPE
If a conditional jump branches to an address that is reached sequentially (no
address break in the fetch sample), the disassembler cannot determine if the
branch was taken. If there are two conditional jump instructions close together
that branch to the same fetch line, then the disassembler may not be able to
determine which conditional jump was actually taken. You can use the mark
cycle function to correct the disassembly. Refer to Marking Cycles later in this
section.
Software Display Format
Control Flow Display
Format