Vl-Cbr-0203 External Battery Module; Real Time Clock (Rtc); Push-Button Reset; Figure 9. Vl-Cbr-0203 Latching Battery Module - VersaLogic VL-EBX-38 Hardware Reference Manual

VL-CBR-0203 E
The VL-CBR-0203 external battery module is compatible with the EBX-38. For more
information, contact Sales@VersaLogic.com.

Figure 9. VL-CBR-0203 Latching Battery Module

Real Time Clock (RTC)

The EBX-38 features a real-time clock/calendar (RTC) circuit. The RTC can be set using the
BIOS Setup utility.
The EBX-38 supplies RTC voltage in S4, S3, and S0 states, but requires an external +2.75 V to
+3.3 V battery to maintain RTC functionality and RTC CMOS RAM when the board is not
powered. The battery connection can be made to any and all of the following:

B2 on-board battery socket per the V8 jumper placed on pins 1-2

J8 external battery connector

J4 user I/O connector

Push-Button Reset

User I/O connector J4 includes an input for a push-button reset switch. Shorting J4, pin 18 to
ground causes the EBX-38 to reboot.
The input can be connected to ground using the normally open contacts of a pushbutton switch or
a relay, or with a switching transistor (open-collector or open-drain) capable of sinking 3.3 mA
with a voltage drop that is less than 500 mV (there is a 1 kΩ resistor on the EBX-38 pulled up to
3.3 V). Do not add an external pull-up resistor to this signal.

Integrator's Note:
The reset button has a switch de-bounce circuit in the FPGA that requires the button to be held
asserted at least 125 ms (1/8 second) to reset the board. Holding the reset asserted on a
Bay Trail processor does not continue to hold the processor in reset; it only resets on the edge of
the assertion that follows the 125 ms de-bounce time interval).
A reset button is provided on the CBR-4005B paddleboard. See Figure 24 on page 52 for the
location of the reset button on the CBR-4005B paddleboard.
EBX-38 Hardware Reference Manual
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XTERNAL ATTERY ODULE
Board Features
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