Clear Breakpoint (Cb) - Texas Instruments 990 Operation Manual

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DP20 Breakpoint specification error. Required index number
may be invalid or missing, or the PC value (memory
address) may have been omitted.
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Application notes: The PC value for a breakpoint must point to the first word of a multiword
instruction.
A breakpoint occurs before the execution of the instruction to which it points.
If a snapshot is associated with a breakpoint, execution of the user program resumes after the
snapshot is printed. If no snapshot is associated with the breakpoint, execution terminates and
?:XJMIP.
accepts another command.
If more than one breakpoint is associated with a specific location, only the first (lowest
numbered) will be found.
If
(1)
the execution is under the control of the Execute User Program under SIE or Trace (RU)
command with an instruction count, (2) a breakpoint occurs, and (3) a new count is not
specified on the next RU command, then, when execution is resumed, counting is continued as
if no breakpoint was encountered:
Breakpoints are not active when the user code is executed with the EX command.
An error
is
not reported when a Set Breakpoint (SB) command redefmes an already defined
;' breakpoint~ The specified breakpoint is modified to take on the new definition.
When an instruction has been fetched from a breakpoint location a number of times equal to the
contents of the reference counter, the breakpoint
is
activated.
Examples:
.580,1000,1,2
.58 1,1000,1,0
.582,1004
The first two examples set a breakpoint at address 1000 on the frrst reference to that address for
an instruction fetch. The frrst example sets breakpoint index number 0 with snapshot index
number 2 to be displayed, and the second example sets breakpoint index number 1 with
snapshot indexnurnber 0 to be displayed. The third example specifies breakpoint index number
2 to be taken at memory location 1004
16 ,
No snapshot is printed, and execution of the user
program terminates after the breakpoint is encountered.
'3.4.24 CLEAR BREAKPOINT (CB). The Clear Breakpoint command is used to disable
previously specified breakpoints.
Syntax definition:
CB
[k.J
[<starting breakPOint>]
[{i, . .
J
<ending breakPOint>]]
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