Software Functional Overview
z IRQ Map
IRQ# Description
IRQ 0 System Timer
IRQ 1 Keyboard
IRQ 2 [Cascade]
IRQ 3 PHS (Serial)
IRQ 4 Serial Port
IRQ 5 Audio/VGA/USB
IRQ 6 Floppy Disk Drive
IRQ 7 Parallel Port
IRQ 8 RTC Alarm
IRQ 9 ACPI
IRQ10 LAN / Modem or Combo, (Card Bus), IEEE 1394
IRQ11 Reserved for PCMCIA card
IRQ12 PS/2 Mouse
IRQ13 FPU (FERR)
IRQ14 Hard Disk Drive
IRQ15 CD-ROM or DVD-ROM
3.4 GPIO Pin Assignment
The GPI and GPO pins connected to system devices. The BIOS can get device’s status and
control the device via the GPI and GPO pins.
• SiS645DX GPI pin assignment
GPIO
Number
Signal Name Default I/O Notes
GPIO0 LPC_PME0 1 I 0 : LPC_PME0 Event Enable
1 : normal operation
GPIO1 PMUFLASH0 1 O 0 : Flash PMU08 firmware
1 : normal operation
GPIO2 MB_ID0 1 I 0 : Mother Board ID0 Select
1 : normal operation
GPIO3 Q_SMI0 1 I 0 : External K/B SMI0
1 : normal operation
GPIO4 N.C. -- -- --
GPIO5
GPRSFW_DET 1 I 0 : Updated GPRS F/W
1 : normal operation
GPIO6 N.C. -- -- --
GPIO7 EC_SCI0 1 I 0 : PMU SCI Detect
1 : PMU SCI Not Detect
GPIO8
PM_RI0 1 I 0 : wakeup event input enable
1 : wakeup event input disable
3-14 FIC M295 / M296 Service Manual
