
ÉlanSC310 Microcontroller Evaluation Board User’s Manual
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PMC0
This pin is logically ORed with the system Reset pin from the ÉlanSC310
microcontroller (RSTDRV) and fed to the reset pin of the 8042 keyboard controller.
It is used to perform a software reset to the 8042. A value of 1 drives the reset pin
of the 8042 active. A value of 0 allows for normal operation. The ÉlanSC310
microcontroller Index ACh bits 3:0 control PMC0 and are set to 0 on power-up.
If you are not using PMU states that turn off the Low Speed PLL (i.e., Doze, Sleep
or Suspend modes) then you do not need to change the settings for this pin. Refer
to “8042 Keyboard Controller” on page 4-14 for a further explanation of when you
need to do a software reset.
PMC1
This pin is not used on this board.
PMC2
This pin is used to select whether the internal ÉlanSC310 microcontroller (serial
port 1) and the Super I/O (serial port 2) are enabled for RS232 serial data
(PMC2=1), or whether the IR Transmitter/Receiver pair is used to send and receive
serial data on serial port 1, and serial port 2 transmission is disabled (PMC2=0).
The ÉlanSC310 Indexes 80h and 81h control the state of PMC2.
PMC3
This pin is not used on this board.
PMC4
This pin is used to mask the system reset pin from the 8042 keyboard controller
that is fed to the Reset CPU pin (RC) of the ÉlanSC310 microcontroller. A value
of 1 holds the CPU’s RC input High, and prevents the 8042 keyboard controller’s
reset output from reaching the CPU. A value of 0 allows for normal operation. The
ÉlanSC310 Index ACh bits 3:0 control this pin and are set to 0 on power-up. If
you are not using PMU states Doze, Sleep, Suspend or Off, then you do not need
to change the settings for this pin.
evalbd.book : ch4 Page 4 Thursday, August 8, 1996 2:34 PM