The RAM drive strength settings configured in Windows CE bootloader versions V4.1, V4.2, andV4.3 could lead to single bit RAM errors on the Colibri PXA270 V2.4C modules. Older versions of the bootloader are not affected by this problem as they already use the drive strength settings as required by the new module versions.
|Product Number||Product Name|
|00082402||Colibri PXA270 312MHz V2.4C|
|00092402||Colibri PXA270 520MHz V2.4C|
|No other hardware versions are affected.|
During extensive burn-in tests on a particular combination of hardware and software revisions we identified stability issues. At elevated temperatures, single bit RAM errors occurred when running Eboot V4.1, V4.2, or V4.3 on Colibri PXA270 V2.4C.
In the critical Eboot revisions, the signal drive strength configured for the RAM signal CLK1 could cause bit errors in the communication between CPU and RAM. The following drive strength register settings solve the problem:
|Module Version||BSCNTR0 value (addr: 0x4800004C)|
|V1.0A to V1.2F||0xFF1FFFFF|
|V1.2G to V2.4B||0xFFFFFFFF|
Use the Windows CE bootloader Eboot V4.4 or newer which sets an optimized drive strength automatically. This is the preferred solution. Note: The bootloader V4.4 isn't available yet but will be available before shipping V2.4C modules.
Continue to use an older bootloader and set the active drive strength in the bootloader configuration block. You can use the ColibriPXA270FixMBS_V2.0 tool or you can set it manually through the bootloader menu.
You can use the ColibriPXA270FixMBS_V2.0 tool which was developed to fix the issue described on this page. The tool evaluates the module HW version and changes the drive strength setting in the config block only if required. Therefore it's safe to run this tool on any Colibri module HW and BSP version. The changes are stored to the config block and also directly applied to the running system. A reboot isn't necessary. You can use the AutoRun feature of the Toradex Windows CE images to automatically execute this tool when attaching any mass storage device like USB Memory Stick, SD Card, etc. Just create a folder called AutoRun in the root directory of the storage device and copy the desired tool into this folder.
There are two versions of this tool in the zip file below
You can edit the config block through the bootloader menu's command prompt or by using the latest config block editor tool (V0.6 or newer). The following example shows the commands in the command prompt mode of the bootloader:
Used Commands: SPACE // to enter bootloader menu x // to enter command prompt mode set mbs.clk1=1 // to set the new drive strength value save mbs // to save the change to flash Perform a reboot to apply the settings The bootloader output should look like this when using the commands above: Toradex Bootloader 4.1 for Colibri Built Sep 14 2012 Press [SPACE] to enter Bootloader Menu BootLoader Configuration: C) Clear Flash Registry X) Enter CommandPrompt Mode D) Download image to RAM now F) Download image to FLASH now L) Launch existing flash resident image now Enter your selection: x >set mbs.clk1=1 >save mbs >
Please refer to the register settings explained in the section Detailed Information above.