CHAPTER 13 S1C88 FAMILY DEBUGGER
S5U1C88000C MANUAL II
EPSON
151
WORKBENCH/DEV TOOLS/OLD ASSEMBLER
s
(step)
Function
This command single-steps the target program from the current PC position by executing one instruc-
tion at a time.
Format
>s [<step>]
↵
(direct input mode)
<step>:
Number of steps to be executed; decimal (default is 1)
Condition: 0
≤
step
≤
65,535
Operation
(1) Step execution
If the <step> is omitted, only the program step at the address indicated by the PC is executed, other-
wise the specified number of program steps is executed from the address indicated by the PC.
>s
↵
...Executes one step at the current PC address.
>s 20
↵
...Executes 20 steps from the current PC address.
The program execution is suspended by the following cause even before the specified number of steps
is completed.
• The [Key Break] button is clicked or the [Esc] key is pressed
After each step is completed, the register contents in the [Register] window are updated. If the
[Register] window is closed, the register contents are displayed in the [Command] window same as
executing the rd command.
When program execution is completed by stepping through instructions, the system stands by
waiting for command input. If you hit the [Enter] key here, the system single-steps the program in the
same way again.
(2) HALT and SLEEP states and interrupts
When the halt or slp instruction is executed, the CPU is placed in standby mode. An interrupt is
required to clear this mode. The debugger has a mode to enable or disable an external interrupt for
use in a single-step operation.
External interrupt
halt and slp instructions
Enable mode
Interrupt is processed.
Executed as the halt instruction.
Processing is continued by an
external interrupt or clicking on
the [Key Break] button.
Disable mode
Interrupt is not processed.
The halt and slp instructions are
replaced with a nop instruction as
the instruction is executed.
In the initial settings, the debugger is set to the interrupt disable mode.
The interrupt enable mode can be set using the [Run | Setting...] menu item.
(3) Execution cycle counter
After the last step is completed, the debugger displays the number of executed cycles and execution
time in the [Command] window. (Refer to Section 13.8.4 for details.)
The execution cycle counter is reset each time the s command is issued.
(4) During log mode
If the program is single-stepped after turning on the log mode, the same contents as when executing
the rd command are displayed in the [Command] window after the last step is completed.