PC87309 Datasheet, PDF (17/192 Pages) National Semiconductor (TI) – PC87309 SuperI/O Plug and Play Compatible Chip in Compact 100-Pin VLJ Packaging

Signal/Pin Connection and Description
Signal/Pin Pin
Name Number
Module
I/O and
Group #
Function
RI2,1
RTS2,1
SIN2,1
SLCT
SLIN
SOUT2,1
STB
STEP
TC
TRK0
V_DD
V_SS
WAIT
97,87
98,88
99,89
69
73
100,92
67
51
25
55
90,41
91,65,40,
15
66
UART1
Input Ring Indicators (Modem) – When low, this signal indicates that a
Group 1 ^{telephone ring signal has been received by the modem.}
The RI1 and RI2 pins have schmitt-trigger input buffers.
RI2 is multiplexed with DENSEL and available only in Two-UART
mode.
UART1,
UART2
Output Request to Send – When low, these output signals indicate to the
Group 12 ^{modem or other data transfer device that the corresponding UART1}
or UART2 is ready to exchange data.
A Master Reset (MR) sets RTS to inactive high. Loopback operation
holds it inactive.
RTS2 is multiplexed on pin 98 with IRSL1 and ID1, and available only
in Two-UART mode. RTS1 is multiplexed on pin 88 with BADDR1.
UART1,
UART2
Input Serial Input – This input signal receives composite serial data from
Group 1 ^{the communications link (peripheral device, modem or other data}
transfer device).
SIN2 is multiplexed on pin 99 with ID3 and available only in Two-
UART mode.
Parallel Port Input Select – This input signal is set active high by the printer when the
Group 2 ^{printer is selected. This pin is internally connected to a nominal 25 KΩ}
pull-down resistor.
Parallel Port
I/O Select Input – When this signal is active low it selects the printer.
Group 8 ^{This signal is in TRI-STATE after a 0 is loaded into the corresponding}
control register bit. Use an external 4.7 KΩ pull-up resistor.
This signal is multiplexed with ASTRB.
UART1,
UART2
Output Serial Output – This output signal sends composite serial data to the
Group 12 ^{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 on pin 100 with IRRX2, IRSL0 and ID0, and is
available only in Two-UART mode.
SOUT1 is multiplexed on pin 92 with CFG0.
Parallel Port
I/O Data Strobe – This output signal indicates to the printer that valid
Group 8 ^{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 KΩ pull-up resistor should be employed.
For Input mode see bit 5, described in Section 4.5.16.
This signal is multiplexed with WRITE.
FDC
Output Step – This output signal issues pulses to the disk drive at a software
Group 11 ^{programmable rate to move the head during a seek operation.}
ISA-Bus
Input DMA Terminal Count – The DMA controller issues TC to indicate the
Group 1 ^{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.
FDC
Input Track 0 – This input signal indicates to the controller that the head of
Group 1 ^{the selected floppy disk drive is at track 0.}
Power
Supply
Input Main 5 V Power Supply – This signal is the 5 V supply voltage for
the digital circuitry.
Power
Supply
Output Ground – This signal provides the ground for the digital circuitry.
Parallel Port Input Wait – In EPP mode, the parallel port device uses this signal to
Group 2 ^{extend its access cycle. WAIT is active low. This signal is multiplexed}
with BUSY. See TABLE 4-12 on page 101 for more information.
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