FDC37B78X SMSC Corporation, FDC37B78X Datasheet - Page 169

• Manufacturer Part Number: FDC37B78X
• Description: Enhanced Super I/O Controller with ACPI Support/ Real Time Clock and Consumer IR
• Manufacturer: SMSC Corporation

CONFIGURATION
The Configuration of the FDC37B78x is very
flexible and is based on the configuration
architecture implemented in typical Plug-and-
Play components. The FDC37B78x is designed
for motherboard applications in which the
resources required by their components are
known.
architecture, the FDC37B78x allows the BIOS to
assign resources at POST.
SYSTEM ELEMENTS
Primary Configuration Address Decoder
After a hard reset (RESET_DRV pin asserted) or
Vcc Power On Reset the FDC37B78x 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)
Configuration Mode.
Note 1:If using TTL RS232 drivers use 1K pull-down. If using CMOS RS232 drivers use 10K pull-
down.
Note 2: The configuration port base address can be relocated through CR26 and CR27.
CONFIG PORT (Note 2)
INDEX PORT (Note 2)
DATA PORT
PORT NAME
by
With its flexible resource allocation
placing
The BIOS uses these
the FDC37B78x into
0x03F0
0x03F0
INDEX PORT + 1
(Pull-down resistor)
Refer to Note 1
SYSOPT= 0
169
configuration ports to initialize the logical
devices at POST. The INDEX and DATA ports
are only valid when the FDC37B78x is in
Configuration Mode.
The SYSOPT pin is latched on the falling edge
of the RESET_DRV or on Vcc Power On Reset
to determine the configuration register's base
address. The SYSOPT pin is used to select the
CONFIG
Once powered up the configuration port base
address can be changed through configuration
registers CR26 and CR27. The SYSOPT pin
is a hardware configuration pin which is
shared with the nRTS1 signal on pin 115.
During reset this pin is a weak active low signal
which sinks 30µA. 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.
0x0370
0x0370
(10K Pull-up resistor)
PORT's
SYSOPT= 1
I/O address at power-up.
Write
Read/Write
Read/Write
TYPE