Technical Document #40

Doc ID:	40
Product:	WinDriver
Version:	--

How do I call WD_Transfer() in the Kernel PlugIn interrupt handler?

You can call WD_Transfer() from within the KP_IntAtIrql() or KP_IntAtDPC() functions in order to access the hardware (see below).

Please note that you can also access the memory/IO directly from within the Kernel PlugIn interrupt functions. [For direct memory access, use the kernel mapping of the memory, returned from WD_CardRegister() in cardReg.Card.Item[i].I.Mem.dwTransAddr].

When calling WD_Transfer() you will need to pass as the first argument a handle to WinDriver (hWD). You can refer to Technical Document #38 to find out how to obtain a handle to WinDriver from within the Kernel PlugIn.

As specified in the aforementioned Technical Document, you can store the handle to WinDriver in a global Kernel PlugIn variable (recommended), or pass it from one function to another. Below is an example of passing a handle to WinDriver from KP_Open() to KP_IntAtIrql():

Add the following line to KP_Open() :

*ppDrvContext = (PVOID) hWD;

Add the following line to KP_IntEnable() :

*ppIntContext = pDrvContext;

You can now use WD_Transfer() in order to access memory/IO from within KP_IntAtIrql(). For example (IO access):

HANDLE hWD = (HANDLE) pIntContext;
WD_TRANSFER trans;
BZERO(trans);
trans.cmdTrans = WP_BYTE;
trans.dwPort = 0x378;
trans.Data.Byte = 0x65;
WD_Transfer(hWD, &trans);

This will write 0x65 to port 0x378 upon interrupt. The hWD handle is passed from KP_Open() to KP_IntEnable() to KP_IntAtIrql() via the context.
[Beginning with version 5.20 of WinDriver you can also view the generated DriverWizard Kernel PlugIn code for an example of calling WD_MultiTransfer() from KP_IntAtIrql(), provided you have used the DriverWizard to define and assign the register/s for the interrupt acknowledgment before generating the code.]

Back to Top

USB Software

Jungo provides a complete and integrated array of USB software solutions, allowing you to complete your projects rapidly and with total confidence.

Products ranging from Embedded USB Software, through USB Software Communication Drivers, to USB Software Testing, icluding innovative and unique USB software patents, allowing our customers to gain a competative edge.

PCI Software

Our extensive solutions portfolio of PCI software may fit any developer/team who is interested in a rapid development of PCI/PCI-Express connectivity software components.