TVicHw32.DLL version 2.0
Copyright (C) 1997 Victor Ishikeev e-mail: [email protected] Portions Copyright (C) 1997 EnTech Taiwan e-mail: [email protected]
AS_DLL.TXT
CONTENTS ========
1. GENERAL TVicHW32 FUNCTIONS 2. DIRECT MEMORY ACCESS WITH TVicHW32 3. DIRECT PORT I/O WITH TVicHW32 4. HARDWARE INTERRUPT HANDLING WITH TVicHW32 5. CONTACT INFORMATION
1. GENERAL TVicHW32 FUNCTIONS ====================================================
TVicHW32 has the following general functions:
bool VICFN OpenTVicHW32(void); ------------------------------- Loads the vichwXX.vxd (under Windows 95) or vichwXX.sys (under Windows NT) kernel-mode driver, providing direct access to the hardware. If the kernel-mode driver was successfully opened, the IsDriverOpened() returns True; if the function fails, the IsDriverOpened() returns False.
void VICFN CloseTVicHW32(void); ---------------------- Closes the kernel-mode driver and releases memory allocated to it. If a hardware interrupt was "unmasked", the "mask" is restored. If the driver was successfully closed, the IsDriverOpened() always returns False.
bool VICFN IsDriverOpened (void); ----------------------------------------------
This boolean function specifies whether the kernel-mode driver is open. Returns True if the driver is already open, or False if it is not.
2. DIRECT MEMORY ACCESS WITH TVicHW32 =====================================
The following function permits direct memory acccess:
void* VICFN MapPhysToLinear(DWORD PhAddr, DWORD Size); ---------------------------------------- ---------------------- Maps a specific physical address to a pointer in linear memory, where PhAddr is the base address and Size is the actual number of bytes to which access is required.
Note that a subsequent call to MapPhysToLinear invalidates the previous pointer.
The following example returns a pointer to the system ROM BIOS area:
char *pBios;
OpenVicHW32();
if (IsDriverOpened()) {
pBios = MapPhysToLinear (0xF8000,256); file://255 bytes beginning at $F8000
file://...working with pBIOS...
CloseVicHW32();
}
else ... // failed
3. DIRECT PORT I/O WITH TVicHW32 ================================
The following functions permit direct I/O port access: ------------------------------------------------------
BYTE VICFN ReadPort (WORD wPortAddress); // read one byte WORD VICFN ReadPortW (WORD wPortAddress); // read one word DWORD VICFN ReadPortL (WORD wPortAddress); // read four bytes void VICFN WritePort (WORD wPortAddress, BYTE bData); // write one byte void VICFN WritePortW (WORD wPortAddress, WORD wData); // write one word void VICFN WritePortL (WORD wPortAddress, DWORD lData); // write four bytes
void VICFN SetHardAccess(bool HardAccess); ------------------------------------------- The SetHardAccess() function determines whether the kernel-mode driver should use "hard" or "soft" access to the I/O ports. If set to True "hard" access is employed; if set to False "soft" access is employed.
"Soft" access provides higher performance access to ports, but may fail if the port(s) addressed are already in use by another kernel-mode driver. While slower, "Hard" access provides more reliable access to ports which have already been opened by another kernel-mode driver.
bool VICFN TestHardAccess(void); --------------------------------- Returns True is "hard" access is used.
4. HARDWARE INTERRUPT HANDLING WITH TVicHW32 ============================================
In a Win32 environment, hardware interrupts are normally prohibited by Windows; the TVicHW32 kernel-mode driver allows you to use the interrupt for direct handling by your application. Note that only one interrupt can be handled at a time.
The following functions permit access to hardware interrupts.
void VICFN SetIRQ(BYTE IRQNumber, void * lpfnOnHwInterrupt); -------------------------------------------------------------
Assign the interrupt specified by the IRQNumber value (1..15) to the lpfnOnHwInterrrupt() handler. If success then IsIRQSet() function (see below) returns True. Note that IRQ0 (the system timer) is *not* supported.
bool VICFN IsIRQSet(void); ---------------------------------------- Specifies whether the hardware interrupt handler has been created by the SetIRQ method.
void VICFN UnMaskIRQ(void); ---------------------------- Physically unmasks the hardware interrupt specified by the IRQNumber property, so that an lpfnOnHWInterrupt function will be generated when a hardware interrupt occurs.
void VICFN MaskIRQ(void); -------------------------- Physically masks the hardware interrupt specified by the IRQNumber value.
bool VICFN IsMasked(void); --------------------------- Function which specifies whether the hardware interrupt handler has been physically masked (True).
void VICFN DestroyIRQ(void); ----------------------------- Frees the memory and code previously assigned for the hardware interrupt specified by the IRQNumber value.
DWORD VICFN GetInterruptCounter(void); -------------------------------------- Function which counts the number of hardware interrupts intercepted by the TVicHW32 kernel-mode driver. The GetInterruptCounter() function is provided largely for debugging purposes, allowing you to compare the actual number of hardware interrupts generated with the number processed by your application.
void VICFN SimulateHWInt(void); ------------------------------- This function is provided for purposes of debugging, and allows you to simulate a hardware interrupt. When this procedure is called, the TVicHW32 kernel-mode driver will feign a "hardware interrupt", without directly affecting the hardware.
5. CONTACT INFORMATION ======================
Comments, questions and suggestions regarding TVicHW32 can be directed by e-mail to [email protected] or [email protected].
With best wishes,
Victor Ishikeev Jun 1997

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