This page last changed on Apr 01, 2008 by bobh.

Interrupt Assignments

Mostly from /proc/interrupts, but it appears to have missed at least one?   

  0:     120642          XT-PIC  timer
  1:       1327          XT-PIC  i8042
  2:          0          XT-PIC  cascade
  4:        223          XT-PIC  serial
  6:          3          XT-PIC  floppy
  8:          1          XT-PIC  rtc
  9:          0          XT-PIC  acpi
 10:       1443          XT-PIC  eth0
 11:          0          XT-PIC  CS5535 Audio
 14:       1981          XT-PIC  ide0
 15:         24          XT-PIC  ehci_hcd:usb1, ohci_hcd:usb2
NMI:          0
LOC:          0
ERR:          0
MIS:          0

Missing from /proc/interrupts:
  3:                      serial (ttyS1)
  5:                      Assigned to PCI bus, according to BIOS (also 10, 11, 15)
  7:                      Was assigned to parallel port, I turned it off in BIOS
                          DMM-32X-AT A/D board jumpered for IRQ 7, but we don't use it
                          (would need to install Diamond drivers to enable it)

I/O Port Assignments


0000-001f : dma1
0020-0021 : pic1
0040-0043 : timer0
0050-0053 : timer1
0060-006f : keyboard
0070-0077 : rtc
0080-008f : dma page reg
00a0-00a1 : pic2
00c0-00df : dma2
00f0-00ff : fpu
01f0-01f7 : ide0
02f8-02ff : serial
03c0-03df : vga+
03f2-03f5 : floppy
03f6-03f6 : ide0
03f7-03f7 : floppy DIR
03f8-03ff : serial
0cf8-0cff : PCI conf1
1000-11ff : 0000:00:0f.0
1400-15ff : 0000:00:10.1
1800-18ff : 0000:00:0f.0
1c00-1cff : 0000:00:10.0
2000-201f : 0000:00:0f.0
6000-7fff : 0000:00:0f.0
9c00-9c3f : 0000:00:0f.0
  9c00-9c03 : ACPI PM1a_EVT_BLK
  9c0c-9c0d : ACPI PM2_CNT_BLK
  9c10-9c13 : ACPI PM_TMR
  9c18-9c1f : ACPI GPE0_BLK
  9c28-9c29 : ACPI PM1a_CNT_BLK
9d00-9d7f : 0000:00:0f.0
9e00-9e07 : 0000:00:01.0
  9e00-9e05 : ACPI CPU throttle
ac1c-ac1f : 0000:00:01.0
df00-df7f : 0000:00:0f.3
  df00-df7f : CS5535 Audio
dfc0-dfff : 0000:00:0e.0
  dfc0-dfff : e100
eff0-efff : 0000:00:0f.2
  eff0-eff7 : ide0

Added (not in any kernel driver, hence not above; we do I/O directly to these)

0x300 - 0x30F : Diamond DMM-32X-AT A/D board
0x310 - 0x311 : RTD DM6952HR Relay Board
0x320 - 0x321 : Second RTD DM6952HR Relay Board, if needed

Memory Mapped I/O

Discover these via 'dmesg | grep tty'
0xefc00000 - 0xefc00fff - Memory mapped I/O for ConnectTech Xtreme/104-Plus Octal UART board

(It uses interrupt 15, apparently sharing with USB?)

Document generated by Confluence on Feb 03, 2026 14:29