ChipSHOUTER Users Manual
: External Connections
24
The SMB trigger input can be configured in one of three
modes:
•
Active-low pulse, high-impedance (approx. 2K
Ω
).
•
Active-high pulse, high-impedance (approx. 2K
Ω
).
•
Active-high pulse, 50
Ω
impedance (DEFAULT).
A suitable pulse for this input can be generated by a
laboratory pulse generator, a custom FPGA or other board, or
the ChipWhisperer.
If interfacing with ChipWhisperer, the recommended meth-
od is to use the HS-OUT SMA connector on the CW506 advanced
breakout board. This requires you to configure that the
glitch out is routed to the HS-OUT pin.
You can also use the active-low pulse method with the
ChipWhisperer “glitch” connector, by enabling the low power
(LP) glitch crowbar output. The ChipSHOUTER has an internal
pull-up on the hardware trigger input, allowing the LP-
glitch crowbar output to serve as an open-drain output. See
the online documentation for more details.
Note that internally this hardware trigger is also rout-
ed to the microcontroller. The microcontroller needs to know
when a fault is being inserted, as this (a) resets the arm
timeout count, and (b) tells the microcontroller to ignore
invalid temperature readings that occurring during a dis-
charge event due to noise on the temperature sensor. If your
trigger source does not have a strong enough drive, it may
be possible to trigger the actual fault injection without
the microcontroller being aware.
This typically results in (1) the device automatically
disarming during use, and (2) a “temperature sensor error”
fault. Ensure you are driving to proper 3.3 LVCMOS levels,
