
ÉlanSC310 Microcontroller Evaluation Board User’s Manual
2-25
1.
0
Suspend/Resume
The ÉlanSC310 microcontroller evaluation board provides a hardware option to
allow the user to toggle between the High Speed and Suspend modes. By pressing
the Suspend/Resume button after the system has powered up, the system enters the
Suspend mode (assuming the ACIN signal is low). By pressing the Suspend/
Resume button again, the system returns to High Speed mode. The behavior of the
system in Suspend mode depends on the BIOS.
Power Management Simulation
Battery backup conditions can be simulated on the evaluation board by controlling
the ACIN signal to the ÉlanSC310 microcontroller. When ACIN is low, power
management functions on the ÉlanSC310 microcontroller are enabled. When
ACIN is high, power management functions on the ÉlanSC310 microcontroller
are disabled. Switch 8 on SW4 controls the ACIN pin on the ÉlanSC310, allowing
power management functions to take effect if they are enabled.
In order to get true power measurements while in Suspend mode, IRQ1 and PIRQ1
must be disconnected from the ÉlanSC310 microcontroller. The ÉlanSC310
microcontroller drives these signals low during Suspend mode. Since the
peripherals connected to these lines drive them high, this creates the appearance
of additional power drain. These signals can be easily disconnected while in
Suspend mode using switches 2 and 3 on SW4.
Before exiting from Suspend mode, IRQ1 and PIRQ1 must be reconnected for the
system to function properly.
SW4-8
ACIN
ON
GND
OFF
5 V
SW4-2
PIRQ1
ON
Connect
OFF
Disconnect
SW4-3
IRQ1
ON
Connect
OFF
Disconnect
evalbd.book : ch2 Page 25 Thursday, August 8, 1996 2:34 PM