Display/modify the memory contents during program execution

2.13.1.4 Display/modify the memory contents during program execution

The Memory panel/Watch panel has the real-time display update function that can update/modify the display contents of the memory/watch-expression in real-time while executing the program.

Using the real-time display update function allows you to display/modify the value of memory/watch-expression not only while the program is stopped, but also in execution.

The real-time display update function is realized by the CPU's/debug tool's RRM function (reading) [Simulator], RAM monitor function (reading) [Full-spec emulator][E1][E20] and DMM function (modifying). Each function has a different area that can be used for reading and writing.

Enable the real-time display update function by making the basic settings below on the [Debug Tool Settings] tab of the Property panel.

Table 2.9

Basic Settings for Real-time Display Update Function

Category	Property	Set Value
[Access memory while running]	[Update display during the execution]	[Yes] (default)
[Access memory while running]	[Display update interval[ms]]	[Integer number between 100 and 65500]

Caution 1.

Local variables are not subject to the real-time display update function.

Caution 2.

When a 2-, 4-, or 8-byte variable is to be read through the RRM or RAM monitor function, the process of assigning a value to the variable may be divided into two steps.
If reading of the variable takes place between the two steps, an incorrect value may be read out because the assignment is not completed.

Caution 3.

The contents of memory or watch expressions can be read for access in all PEs when the selected microcontroller supports multi-core. In the Local RAM self area, note that they can be read only for the access in the currently selected PE.

Remark

See "2.13.1.3 Modify the memory contents" or "2.13.6.6 Modify the contents of watch-expressions" for details on how to modify values in the Memory panel/Watch panel.

(1)	RRM function (reading) [Simulator]

This function is used to read the contents of memory or of watch-expressions in real-time during execution of a program.

The following area can be read by the RRM function. Memory and watch-expressions allocated to this area can always be displayed in real-time.

Table 2.10

Target Area of RMM Function

Area	Simulator
Area	Simulator
Internal ROM
Internal RAM
Peripheral I/O area	-
Data flash	-
Emulation memory	-
Target memory	-
CPU register	Note
I/O register (except read-protected I/O registers)

Note	Impossible during tracer/timer execution

(2)	RAM monitor function (reading) [Full-spec emulator][E1][E20]

This function is used to read the contents of memory or a watch-expression via the CPU's RAM monitor function.

The following area can be read by the RAM monitor function.

Caution

If CPU status shifts to the standby mode (HALT/STOP/IDLE) mode, a monitor time-out error will occur.

Table 2.11

Target Area of RAM Monitor Function

Area	Full-spec emulator	E1/E20
Internal ROM	-	-
Internal RAM
Peripheral I/O area	-	-
Data flash (except ID tag)	-	-
Target memory	-	-
CPU register	-	-
I/O register	-	Note

Note	Possible only for the RH850G4MH

Note that to enable the RAM monitor function, the setting below is required in addition to the Basic Settings for Real-time Display Update Function.

Debug Tool	Category	Property	Set Value
Full-spec emulator E1/E20	[Access memory while running]	[Access during the execution]	[Yes]

(3)	DMM function (modifying)

This function is used to write to the memory or watch-expressions in real-time during execution of a program.

The following area can be modified by the DMM function.

Caution 1.

If a value is written through the DMM function, the atomicity cannot be guaranteed.

Caution 2.

If CPU status shifts to the standby mode (HALT/STOP/IDLE) mode, a monitor time-out error will occur.

Table 2.12

Target Area of DMM Function

Area	Full-spec emulator	E1/E20	Simulator
Internal ROM	-	-
Internal RAM
Peripheral I/O area	-	-	-
Emulation memory	-	-	-
Target memory	-	-	-
CPU register	-	-	Note 1
I/O register (except read-protected I/O registers)	-	Note 2

Note 1.

Impossible during tracer/timer execution

Note 2.

Possible only for the RH850G4MH

To enable the DMM function, the setting below is required in addition to the Basic Settings for Real-time Display Update Function.

Debug Tool	Category	Property	Set Value
Full-spec emulator E1/E20	[Access memory while running]	[Access during the execution]	[Yes]
Simulator	No setting is required.

The memory values/watch-expressions updated by the real-time display update function are highlighted in pink on the Memory panel/Watch panel.

Figure 2.41

Example of Memory Display by Real-time Display Update Function