INFO: PCMCIA Interrupt Sharing Under Windows 98

ID: Q222821

The information in this article applies to:

SUMMARY

PCMCIA devices can utilize either shared (PCI) interrupts or non-shared (ISA) interrupts. Windows 98 determines the requested interrupt type by examining the TPCE_IR Interrupt Request Description Structure in the Configuration Table Entry Tuple. If the Share bit (bit 7) is set, Pccard.vxd attempts to route the card's IREQ# line to a PCI interrupt. If the Share bit is not set, PCCARD routes IREQ# to an ISA interrupt. If PCCARD determines that there are no interrupt lines of the proper type available, it will fail the CONFIG_FILTER message, causing the device to display error code 7 (CM_PROB_FAILED_FILTER) in Device Manager.


MORE INFORMATION

Under Windows 98 PCCARD enables PCMCIA IRQ sharing by default only for Modem class devices. PCCARD also enables IRQ sharing if it finds a registry value named EnableIRQSharing in the device's software registry branch with a nonzero value. For example, in an inf AddReg section you could use the following line to force PCCARD to allow IRQ sharing: 


HKR,,EnableIRQSharing,1,01,00,00,00

Additional query words: 


Keywords          : kbDDK kbWinOS98 
Version           : Win98:
Platform          : Win98 
Issue type        : kbinfo

Last Reviewed: May 5, 1999