h6. [[Hardware Abstraction Layer]] h6(. [[HAL entry points from RISC OS]] h6((. » HAL_PCISpecialCycle h2. HAL_PCISpecialCycle h5. (HAL entry #94) <pre> void HAL_PCISpecialCycle(uint32_t message) </pre> |_<. Entry | | |message |b0-15 Encoded message number| | |b16-31 Message specific optional data| |_<. Exit | | |- | | h4. Use Performs a special cycle on PCI bus 0, as defined in section 3.6.2 of the PCI 2.2 specification. The 32 bit sideband _message_ value is placed on the bus during the data phase, and encodes a 16 bit message number plus optional 16 bit data value. Special cycles cannot cross PCI bridges, a type 1 configuration write must be used in that instance, so this call only concerns bus 0. This is an internal call for use by the PCI module and should not be used by user software. User software should use the [[PCI SWI Calls|PCI SWIs]] instead of talking to the HAL directly. h4. See also * [[HAL PCI API]] h6. Information source: HAL.Tungsten.doc.PCI_HALAPI in CVS