RadioProcessor
HW Trigger/Reset Header
The short 2x2 IDC header is the Hardware Trigger/Reset connector. This is an input connector, for
hardware triggering (HW_Trigger) and resetting (HW_Reset). Pins 3 and 4 are grounds, and pins 1 and 2 are
the reset and trigger inputs, respectively. Both inputs are pulled high by an on board 10kΩ pull up resistor.
HW_Trigger
(pin 2) When this input is set to logical 0 (for example by shorting it with pin 4), a hardware
trigger is produced. This has the same effects as issuing a trigger through software, although the hardware
trigger is more precise, since there are no software latencies involved.
HW_Reset
(pin 1) When this input is set to logical 0 (for example by shorting it with pin 3), the pulse
program is reset.
Clock Oscillator Header
The RadioProcessor comes with a crystal oscillator mounted at the designated “Clock” header to provide a
timing signal for the board. If required, it is possible to remove the oscillator that comes standard, and instead
drive the RadioProcessor with an external clock signal. The oscillator module can be removed from the board,
and an external signal can be input through the header pins. Do not attempt to drive a RadioProcessor board
with an external clock while an oscillator module is also connected. The standard clock oscillator’s orientation
should be noted - if the clock oscillator is reconnected, it must be inserted in the same orientation or board
damage may occur. The external clock signal must be a TTL square wave, i.e. a digital signal of no more than
3.3 V. This is the absolute maximum allowable voltage, typically a voltage of 1.5-2 V is sufficient. Be aware
that the TTL signal must be a positive-only signal, any negative voltage will damage the programmable-logic
chip.
2020-10-07
25
Figure 11:
Hardware Trigger/Reset Header pin-out.
4
2
3
1
www.spincore.com
Figure 12:
Both the bare header socket and the installed clock module are shown above. Please note
the proper orientation of the 50 MHz clock.
