82374EB Datasheet, PDF (158/208 Pages) Intel Corporation – SYSTEM COMPONENT (ESC)

82374EB 82374SB
290476 – 82
Figure 20 Initialization Sequence for ESC Initialization Command Words (ICWs)
9 5 End-Of-Interrupt Operation
9 5 1 END OF INTERRUPT (EOI)
The In Service (IS) bit can be reset either automatically following the trailing edge of the second internal
INTA pulse (when AEOI bit in ICW1 is set) or by a command word that must be issued to the Interrupt
Controller before returning from a service routine (EOI command) An EOI command must be issued twice with
this cascaded interrupt controller configuration once for master and once for the slave
158