FDC37C669_07 SMSC [SMSC Corporation], FDC37C669_07 Datasheet - Page 118

• Manufacturer Part Number: FDC37C669_07
• Description: PC 98/99 Compliant Super I/O Floppy Disk Controller with Infrared Support
• Manufacturer: SMSC [SMSC Corporation]

The configuration of the chip is programmable
through
registers.
CONFIGURATION REGISTER ADDRESS
The
Registers are located is controlled by the nRTS2
pin. The state of the nRTS2 pin is latched by
the trailing edge of hardware reset.
latched state is a 0, the Configuration Registers
are located at address 3F0H-3F1H.
latched state is a 1, then the Configuration
Registers are located at address 370H-371H.
CONFIGURATION REGISTERS
The configuration registers are used to select
programmable options of the chip. After power
up, the chip is in the default mode. The default
modes are identified in the Configuration Mode
Register
configuration registers, the following sequence
must be followed:
1.
2.
3.
address
Enter Configuration Mode.
Configure the Configuration Registers.
Exit Configuration Mode.
software
Description.
at
which
selectable
To
the
program
Configuration
configuration
CONFIGURATION
If this
If the
the
118
Enter Configuration Mode
To enter the configuration mode, two writes in
succession to port 3F0H (or 370H) with 55H
data are required. If a write to another address
or port occurs between these two writes, the
chip does not enter the configuration mode. It is
strongly
disabled for the duration of these two writes.
Configuration Mode
The
CR00-CR29. These registers are accessed by
first writing the number (0-29H) of the desired
register to port 3F0H (or 370H) and then writing
or reading the configuration register through port
3F1H (or 371H).
Exit Configuration Mode
The configuration mode is exited by writing an
AAH to port 3F0H (or 370H).
Programming Example
The following is an example of a configuration
program in Intel 8086 assembly language.
chip
recommended
contains
configuration
that
interrupts
registers
be