It is possible to enable the nWE (aka DF_ALE_nWE) signal on SODIMM pin 99 by software. This feature is supported with Toradex WinCE BSP 3.7b2 and higher. If nWE is disabled the GPIO on SODIMM pin 99 can be used, otherwise the GPIO must be set to input (default).
The following Colibri modules support this feature:
This feature is controlled by the following registry setting:
[HKEY_LOCAL_MACHINE\System\Config] "SWControlledNWEEnable99" = dword:0 ; 0: default
Setting SWControlledNWEEnable99 to 0 (default)
enables nWE on SODIMM pin 99 at start-up of the Windows CE image. It's not possible to disable this functionality by software.
Setting SWControlledNWEEnable99 to 1
Disables nWE on SODIMM pin 99 at start-up of the Windows CE image. It is possible to enable/disable this functionality by software using IOCTL HAL ENABLENWE. When using this setting the PCCard Driver also uses IOCTL HAL ENABLENWE to enable the nWE functionality when a card is plugged-in and to disable it when the card gets plugged out. Don't use this setting when you are using removable PCCards (e.g. CompactFlash storage) and you also have an other device using nWE on SODIMM pin 99 (e.g. VLIO device).
If you are not using Toradex Windows CE (e.g. Linux) please contact Toradex about how to enable nWE on SODIMM pin 99.