Pc/104 Bus Interface; Super I/O - Lippert PC/104-Plus Technical Manual

Technical Manual PC/104-Plus "Cool RoadRunner II" Version 1.16

1.8 PC/104 bus interface

The PC/104 bus is a modification of the industry standard (ISA) PC bus specified in IEEE
P996. The PC/104 bus has different mechanics than P966 to allow the stacking of mod-
ules. The main features are:
Supports programmable extra wait state for ISA cycles.
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Supports I/O recovery time for back-to-back I/O cycles.
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The specification for the PC/104 bus and the PC/104-Plus bus are available from the
PC/104 Consortium (http://www.PC104.org).

1.9 Super I/O

The onboard Super I/O (SMSC FDC37B72x) provides:
PC-AT keyboard interface on IDC10 connector
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floppy disk interface on FFC connector
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COM1 and COM2 on IDC10 connectors
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LPT1 on IDC26 connector
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PS/2 mouse interface on IDC16 connector
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IrDA interface on IDC16 connector
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General purpose pins are used for the watchdog functions
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To use the watchdog function of the Super I/O it is necessary to program the registers.
This can be done through the two I/O addresses 370h and 371h. At the I/O address 370h
the index-register is located, at the I/O address 371h the data-register. To change the reg-
isters or to read them the Super I/O controller has to be in configuration mode. Therefore
the data byte 55h has to be written to the I/O address 370h. After configuration the con-
figuration mode can be left by writing AAh to the I/O address 370h. Reading from or writing
to a register works as follows:
On request there are DOS programs SMCW.EXE (to write) and SMCR.EXE (to read)
available that work that way (hex-letters ' a ' to ' f ' have to be entered as small letters)
© LIPPERT Automationstechnik GmbH • Hans-Thoma-Str. 11 • 68163 Mannheim • Tel: 0621/43214-0 • Fax: 0621/43214-30
OUT (0x370, 0x55)
OUT (0x370, register-index)
OUT (0x371, register-data), or IN (0x371, register-data)
OUT (0x370, 0xAA)
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