PC87307VUL National Semiconductor, PC87307VUL Datasheet - Page 21

• Manufacturer Part Number: PC87307VUL
• Description: PC87307/PC97307 Plug and Play Compatible and PC97 Compliant SuperI/O
• Manufacturer: National Semiconductor

SOUT2,1
STB
STEP
SWITCH
TC
TRK0
V
V
V
V
WAIT
WDATA
WDO
Signal/Pin
BAT
CCH
DD
SS
Name
148, 138
112
91
66
35
96
64
65
1, 24, 61,
100, 121,
140
2, 11, 25,
40, 60,
101, 120,
130, 139
111
89
156
Number
Pin
Management
Parallel Port
Parallel Port
RTC and
RTC and
ISA-Bus
UART1,
Module
UART2
Supply
Supply
Power
Power
Power
FDC
APC
FDC
APC
APC
FDC
Signal/Pin Connection and Description
Group 17
Group 13
Group 16
Group 16
Group 10
Group #
Group 7
Group 1
Group 1
Group 2
I/O and
Output
Output
Output
Output
Output
Input
Input
Input
Input
Input
Input
Input
I/O
Serial Output – This output signal sends composite serial data to the
communications link (peripheral device, modem or other data transfer
device).
The SOUT2,1 signals are set active high after a Master Reset (MR).
SOUT2 is multiplexed with CFG3. SOUT1 is multiplexed with CFG0.
Data Strobe – This output signal indicates to the printer that valid
data is available at the printer port.
This signal is in TRI-STATE after a 0 is loaded into the corresponding
control register bit.
An external 4.7 K
This signal is multiplexed wiTH WRITE.
Step – This output signal issues pulses to the disk drive at a software
programmable rate to move the head during a seek operation.
Switch On/Off – Indicates a request to the APC to switch the power
on or off. When V
signal indicates a Switch On request. When V
transition on this pin indicates a Switch Off request.
The pin has an internal pull-up of 1 M
input buffer and debounce protection of at least 16 msec.
DMA Terminal Count – The DMA controller issues TC to indicate
the termination of a DMA transfer. TC is accepted only when a DACK
signal is active.
TC is active high in PC-AT mode, and active low in PS/2 mode.
Track 0 – This input signal indicates to the controller that the head of
the selected floppy disk drive is at track 0.
Battery Power Supply – Power signal from the battery to the Real-
Time Clock (RTC) or for Advanced Power Control (APC) when V
is less than V
resistor.
V
APC when V
Main 5 V Power Supply – This signal is the 5 V supply voltage for
the digital circuitry.
Ground – This signal provides the ground for the digital circuitry.
Wait – In EPP mode, the parallel port device uses this signal to
extend its access cycle. WAIT is active low. It is internally connected
to a nominal 25 K
This signal is multiplexed with BUSY. See Table 6-12 on page 134 for
more information.
Write Data (FDC) – This output signal holds the write
precompensated serial data that is written to the selected floppy disk
drive. Precompensation is software selectable.
WATCHDOG Out – This output pin becomes low when a
WATCHDOG time-out occurs. See “The WATCHDOG Feature” on
page 172. This pin is configured by bit 6 of the SuperI/O
Configuration Register 2.
This signal is multiplexed with GPIO17.
CC
Help Power Supply – This signal provides power to the RTC or
21
CCH
BAT
is higher than V
(by at least 0.5 V). V
DD
pull-up resistor should be employed.
pull-down resistor.
does not exist, a high to low transition on this
Function
BAT
(by at least 0.5 V).
BAT
(nominal), a schmitt-trigger
includes a UL protection
DD
exists, a high to low
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CCH