Difference between revisions of "Read-Modify-Write Flash"
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| − | This article describes how to use the '''Read-Modify-Write (RMW)''' function |
+ | This article describes how to use the '''Read-Modify-Write (RMW)''' function in the J-Link software. This article assumes that there is already a basic knowledge about flash programming in general. |
| + | The following example project will be shown for a Infineon XMC4500 MCU but can be applied to any other MCU. This can for example be used to split physical memory sectors into smaller logical ones. |
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| − | By default the Read-Modify-Write threshold is set to 1 kB. |
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| + | By default the Read-Modify-Write threshold is set to 1 kB in order to allow read-modify-write of single bytes in flash (e.g. when editing bytes in memory windows of IDEs). |
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| − | To increase the threshold J-Link offers the following command string: ''SetFlashDLNoRMWThreshold = <value>'' |
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| + | To increase the threshold J-Link offers the following command string: ''SetFlashDLNoRMWThreshold = <value>'' |
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| − | A more detailed description is available in the J-Link users manual(UM8001). |
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| + | A more detailed description is available in the J-Link User Manual (UM08001). |
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| − | = Minimum requirements = |
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| − | In order to use the example project the following minimum requirements have to be met: |
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| − | * J-Link software version V6.14a or later |
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| − | * J-Link Plus HW version V10.1 or later |
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| − | * Windows PC to execute the .bat file in the example project |
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= Sample project = |
= Sample project = |
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| − | The sample project is designed to be used with J-Link |
+ | The sample project is designed to be used with J-Link and a Infineon XMC4500 MCU. It will we automatically executed when starting the .bat file. |
The .bat and .jlink file can be used as a reference for your own RMW flash projects. |
The .bat and .jlink file can be used as a reference for your own RMW flash projects. |
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= How to = |
= How to = |
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| − | For the example project the ''SetFlashDLNoRMWThreshold'' value |
+ | For the example project the ''SetFlashDLNoRMWThreshold'' value is set to ''0xFFFF'' (64 kB RMW threshold). This means that the J-Link DLL will perform a read-modify-write of flash memory regions <= 64 kB. Make sure you adjust this value depending on the device and sector you are trying to modify. |
To use the example project follow these steps: |
To use the example project follow these steps: |
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Revision as of 11:56, 14 March 2017
Contents
This article describes how to use the Read-Modify-Write (RMW) function in the J-Link software. This article assumes that there is already a basic knowledge about flash programming in general.
The following example project will be shown for a Infineon XMC4500 MCU but can be applied to any other MCU. This can for example be used to split physical memory sectors into smaller logical ones.
By default the Read-Modify-Write threshold is set to 1 kB in order to allow read-modify-write of single bytes in flash (e.g. when editing bytes in memory windows of IDEs).
To increase the threshold J-Link offers the following command string: SetFlashDLNoRMWThreshold = <value>
A more detailed description is available in the J-Link User Manual (UM08001).
Sample project
The sample project is designed to be used with J-Link and a Infineon XMC4500 MCU. It will we automatically executed when starting the .bat file.
The .bat and .jlink file can be used as a reference for your own RMW flash projects.
How to
For the example project the SetFlashDLNoRMWThreshold value is set to 0xFFFF (64 kB RMW threshold). This means that the J-Link DLL will perform a read-modify-write of flash memory regions <= 64 kB. Make sure you adjust this value depending on the device and sector you are trying to modify.
To use the example project follow these steps:
- Unzip the contents of the Wiki_RMW.zip to a example folder
- execute StartTest.bat
- The J-Link commander will open and you should see the following output
- If your output matches the screenshot, the RMW was successful (this applies only to the example project, the output on your own project might vary)
