FDC37C935-QS Standard Microsystems (SMSC), FDC37C935-QS Datasheet - Page 137

• Manufacturer Part Number: FDC37C935-QS
• Manufacturer: Standard Microsystems (SMSC)

Specifications of FDC37C935-QS

• Lead Free Status / RoHS Status: Supplier Unconfirmed

The Configuration of the FDC37C93x is very
flexible and is based on the configuration
architecture implemented in typical Plug-and-
Play components. The FDC37C93x is designed
for motherboard applications in which the
resources required by their components are
known.
architecture, the FDC37C93x allows the BIOS to
assign resources at POST.
SYSTEM ELEMENTS
Primary Configuration Address Decoder
After a hard reset or Power On Reset the
FDC37C93x is in the Run Mode with all logical
devices disabled. The logical devices may be
configured through two standard Configuration
I/O Ports (INDEX and DATA) by placing the
Note 1: If using TTL RS232 drivers use 1K pull-down. If using CMOS RS232 drivers use 10K pull-
Entering the Configuration State
The device enters the Configuration State when
the following Config Key is successfully written
to the CONFIG PORT.
CONFIG PORT
INDEX PORT
DATA PORT
Config Key = < 0x55, 0x55>
PORT NAME
down.
With its flexible resource allocation
0x03F0
0x03F0
INDEX PORT + 1
(Pull-down resistor)
Refer to Note 1
SYSOPT= 0
CONFIGURATION
137
FDC37C93x into Configuration Mode.
BIOS uses these configuration ports to initialize
the logical devices at POST. The INDEX and
DATA
FDC37C93x is in Configuration Mode.
The SYSOPT pin is latched on the falling edge
of the RESET_DRV or on Power On Reset to
determine the configuration register's base
address. The SYSOPT pin is used to select the
CONFIG PORT's I/O address at power-up. The
SYSOPT pin is a hardware configuration pin
which is shared with the nRTS1 signal on pin
148. During reset this pin is a weak active low
signal which sinks 30uA. Note: All I/O addresses
are qualified with AEN.
The INDEX and DATA ports are effective only
when the chip is in the Configuration State.
Exiting the Configuration State
The device exits the Configuration State when
the following Config Key is successfully written
to the CONFIG PORT.
Config Key = < 0xAA>
0x0370
0x0370
(10K Pull-up resistor)
SYSOPT= 1
ports
are
only
Write
Write
valid
Read/Write
TYPE
when
The
the