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Priority
Interrupt
Number
Interrupt Source
17
IRQ7
Parallel Port
n
Note:
A PCMCIA card can use IRQ 3, 4, 5, 7, 9 and 11 as long as it does not
conflict with the interrupt address of any other device.
4.2.2
I/O Subsystem
The I/O subsystem, implemented with an SMC37C655IR Super I/O
Controller Chip, provides for such functions as internal floppy drive control,
serial and parallel ports and support for the Serial Infrared port. The Super
I/O Controller includes the following features:
•
100 percent compatible with ISA, EISA, and micro-channel architectures
•
Built-in floppy disk controller
•
Two UARTs
•
Software compatible with the PC16550A and PC16450
•
MIDI compatible
•
Infrared support on UART2 (IRDA-compliant)
•
Bidirectional Parallel Port
•
Enhanced Parallel Port (EPP) compatible
•
Extended Capabilities Port (ECP) compatible, including level 2
support
•
Bidirectional under either software or hardware control
•
Compatbile with ISA, EISA, and Micro Channel architectures
•
Ability to multiplex FDC signals on parallel port pins for
external FDD
•
Includes protection circuit against damage caused when
printer is powered up, or operated at higher voltages
•
Integral address decoder- provides selection of all primary and
secondary ISA addresses including COM1-4 and LPT1-3.
•
Enhanced Power Management Function
•
Enhanced programmable power-down and wake-up modes
Theory of Operation
4-5