User`s guide

8 • Introduction
1.3.6 Interrupts
Two enhanced interrupt controllers provide the cPCI-6810/6820 with a total of
15 interrupt inputs. Interrupt controller features include support for:
• Level-triggered and edge-triggered inputs
• Individual input masking
• Fixed and rotating priorities
Interrupt sources include:
• Counter/Timers
• Serial I/O
• Keyboard
• Printer Port
• Floppy disk
• IDE interface
• Real-Time Clock
• On-board PCI devices
Enhanced capabilities include the ability to configure each interrupt level for
active high going edge or active low-level inputs. The cPCI-6810/6820’s
interrupt controllers reside in the CNB30LE.
1.3.7 DMA
Two enhanced DMA controllers are provided on the cPCI-6810/6810 for use
by the onboard peripherals. The cPCI-6810/6820's DMA controllers reside in
the CNB30LE device.
1.3.8 Real-Time Clock
The super I/O PC87417 provides DS1287 compatible Real-Time Clock. It
provides a Y2K compliant century calendar as well as a time of day function. In
addition, 242 bytes of battery-backed-up CMOS RAM accessed through
70-71h and 72-73h are available for use by the BIOS. A separate 3V coin cell
battery (PANSONIC CR2032 or compatible) provides battery-back-up