I/O Subsystem - Texas Instruments Extensa 570x Series Maintenance Manual

Priority Interrupt
17 IRQ7
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
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
Bidirectional Parallel Port
Integral address decoder- provides selection of all primary and
secondary ISA addresses including COM1-4 and LPT1-3.
Enhanced Power Management Function
Number
Parallel Port

I/O Subsystem

Software compatible with the PC16550A and PC16450
MIDI compatible
Infrared support on UART2 (IRDA-compliant)
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
Enhanced programmable power-down and wake-up modes
Interrupt Source
Theory of Operation 4-5