MSI MS-6552 Manual page 22

Chapter 2
to make any n ecessary hardware or software setting s for the expansion card,
such as jumpers, switches or BIOS co nfig uration.
CNR (Communication Network Riser)
The CNR slot allo ws you to ins ert the CNR e xpansio n cards . CNR is a
spec ia lly d es ig n ed n etwork, au dio, or mode m riser c ard for ATX fa mily
motherboards. Its main processing is done throug h software and controlled by
the motherboard' s chipset.
PCI Interrupt Request Routing
The IRQ, abbreviation of inte rrupt reque st line and pronounced I-R-Q,
are h ard wa re lin es ove r which dev ice s can se nd interrupt s ig n als to the
microprocessor. The PCI IRQ pins are typically connected to the PCI bus INT
A# ~ INT D# pins as follows:
Order 1 Order 2
PC I Slot 1 IN T A# IN T B#
PC I Slot 2 IN T B# IN T C #
PC I Slot 3 IN T C # IN T D #
2-28
Order 3 Order 4
IN T C # IN T D #
IN T D # IN T A#
IN T A# IN T B#