FDC37B72X_07 SMSC [SMSC Corporation], FDC37B72X_07 Datasheet - Page 135

• Manufacturer Part Number: FDC37B72X_07
• Description: 128 Pin Enhanced Super I/O Controller with ACPI Support
• Manufacturer: SMSC [SMSC Corporation]

signal is 1, the output tristates: an external pull-up
can pull the pin high, and the pin can be shared
i.e., P17 and nSMI can be externally tied together.
When writing to the command and data port with
hardware speedup, the IOW timing shown in the
figure titled “IOW Timing for Port 92” in the
Timing Diagrams Section is used. This setup
nIOW+n60=B
64=I/O Addr
60=I/O Addr
nAfterD1+B
nIOW+n64
nAfterD1
AfterD1
nCNTL
nIOW'
nAEN
nIOW
nDD1
GA20
AEN
DD1
CLK
D[1]
n64
n60
nA
0ns
Gate A20 Turn-On Sequence Timing
136
250ns
In 8042 mode, the pins cannot be programmed as
input nor inverted through the GP configuration
registers.
time is only required to be met when using
hardware speedup; the data must be valid a
minimum of 0 nsec from the leading edge of the
write and held throughout the entire write cycle.
500ns