CHAPTER 8: DEBUGGER

s (step)

Function

This command single-steps the target program from the current PC position by executing one instruction 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

•A map break, etc. occurs

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.

 

Enable mode

Disable mode

External interrupt

Interrupt is processed.

Interrupt is not processed.

 

 

 

halt and slp instructions

Executed as the halt instruction.

The halt and slp instructions are

 

Processing is continued by an

replaced with a nop instruction as

 

external interrupt or clicking on

the instruction is executed.

 

the [Key Break] button.

 

 

 

 

In the initial settings, the debugger is set to the interrupt disable mode.

The interrupt enable mode can also be set by using the md command.

(3)Execution cycle counter

The execution cycle counter displayed in the [Register] window indicates the number of cycles executed or the execution time of the target program.

In the initial debugger settings, the execution cycle counter is set to hold mode so that execution time is added up until the CPU is reset. If this mode is changed to reset mode by the md command, the execution cycle counter is cleared to 0 each time the s command is executed. The counter is also reset simultaneously when execution is restarted by hitting the [Enter] key.

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S5U1C63000A MANUAL

 

 

(S1C63 FAMILY ASSEMBLER PACKAGE)