Texas Instruments 990 Operation Manual page 69

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Example:
.IR
PC=046C WP=OOOO ST=OOOO
.EX
ASM/TERM? A
ASM/TERM?
I
.lR
PC=046C WP=OOOO ST=OOOO
The EX command begins execution with the PC, WP and ST registers equal to the values
obtained when the Inspect Registers (lR) command is invoked. A program run under EX does
not change the contents of these registers. The second IR command shows that the contents
remain the same.
3.4.11 EXECUTE USER PROGRAM UNDER SIE OR TRACE (RU). The Execute User Pro-
gram under SIE or Trace command provides controlled execution of the user's program.
Syntax· definition:
RU
[{i . ..}
<instruction count>]
The command is tenninated by a carriage return.
Parameter:
instruction count Maximum number of instructions to be executed
before returning to command mode. A value of
o
indicates that no instruction limit applies.
Parameter default value: The value of the instruction count at the last entry into command
mode is used as the default value. If the previous RU command has exhausted the instruction
count, the default is 0, implying no instruction limit. The system is initially loaded with a
default value of O.
Description: Instructions in the user's program are executed one at a time using either the
hardware SIE feature or the software trace interpreter. The user may specify one of these two
modes of operation with the Set Trace Region (SR) command (paragraph 3.4.26).
Before the monitor executes a user instruction, it checks whether the instruction is within a
defined trace region. If the instruction is within a trace region, the trace interpreter is called and
the instruction traced. If the instruction is not within a trace region, the instruction is executed
using Single Instruction Execution (SIE. described in paragraph 3.3.1). In both cases, the user's
WP, PC, and ST registers are updated after each instruction executed. The monitor checks
whether a breakpoint has been reached and if so, prints out the user's registers and snapshot, if
defined. If a snapshot is assigned to a breakpoint, the monitor continues execution after the
breakpoint has been reached, without operator intervention. If no snapshot was specified, the
monitor returns control to the command processor. (Refer to the descriptions of the SB and SS
commands in paragraph 3.4.20 and 3.4.23.) If the run count, number of instructions to be
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Digital Systems Division