2.16
Additional user key entry
The V2M-Juno r2 motherboard provides the following methods of additional user key entry:
• Trusted keyboard entry using the secure keyboard entry port on the Juno r2 SoC:
— This method requires a custom external device with decode circuitry for key entry.
— The Juno r2 SoC controls the trusted keyboard over a secure I
2
C bus.
— Supports touch screen display. A touch screen secure keyboard interface board with a built-in
controller enables use of a resistive touch screen.
• Six user push buttons on the V2M-Juno r2 motherboard that emulate hand-held devices. The push
buttons provide access through IOFPGA GPIO.
A single 9-pin Mini-Din socket on the top face of the V2M-Juno r2 motherboard provides a secure
keyboard entry port for text entry using an external keyboard. The following figure shows the additional
user key interface and its connections to the user push buttons on the V2M-Juno r2 motherboard.
Note
One user push button input,
NU/NMI
, to the FPGA is not available to the external secure keyboard
custom device.
Versatile Express
V2M-Juno r2 motherboard
3V3
GND
IOFPGA
NU/NMI
VOL-
VOL+
RLOCK
HOME
POWER
User push
buttons
V-
V+
RL
HM
PW
Juno r2 ARM
Development
Platform SoC
Secure
I
2
C
Secure keyboard and user push buttons
PL061 (0)
Figure 2-19 Additional user key entry interface
The following figure shows an example trusted keyboard design using an external custom device that
connects to the secure keyboard entry port.
2 Hardware Description
2.16 Additional user key entry
ARM 100114_0200_03_en
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