Proton Calorimetry/Experimental Runs/2021/Apr1

Daisy chain tests of second DDC232 prototype in D109

Aim: Debug "mirroring" issues when daisy-chaining more than 2 DDC232s boards. Test signal quality across boards using 500MHz oscilloscope.

Notes

• 3 DDC232 boards have S12915-16R photodiodes.
• 4th DDC232 board has 1k ohm resistors.
• In the runs below, boards are enumerated right to left, with the right-most board (1st board) connected to the FPGA.
• In the configuration column, P = board with photodiodes and R = board with resistors. The first board listed in this column is connected to the FPGA.
• In all runs, an integration time of 170us and full-scale range of 350pC is used.

Traces saved in /unix/www/html/pbt/wikiData/images/DDC232/20210401

Run	Board Configuration	Scope Trace Description	Oscilloscope Trace
1	P	Yellow trace shows DVALID at FPGA, blue shows DVALID at J2 of DDC232 board.
2	P	Yellow trace shows DVALID at FPGA, green shows CLK at J2 of DDC232 board, purple shows 12V at J2 of DDC232 board.
3	P	Yellow trace shows DVALID at FPGA, purple trace shows DOUT at J2 of DDC232 board.
4	P	Green trace shows CLK at J2 of DDC232 board, blue trace shows DCLK at J2 of DDC232 board.
5	P, P	Yellow trace shows DVALID at FPGA, green shows CLK of 1st board at J2, blue shows DCLK of 1st board at J2, purple shows 12V of 1st board at J2.
6	P, P	Yellow trace shows DVALID at FPGA, green shows CLK of 1st board at J2, blue shows DCLK of 1st board at J2, purple shows DOUT of 1st board at J2. The last trace shows the end of a readout cycle.
7	P, R	Yellow trace shows DVALID at FPGA, green shows CLK of 1st board at J2, blue shows DCLK of 1st board at J2, purple shows DOUT of 1st board at J2. The trace shows the transition from photodiode data bits to resistor data bits in the readout cycle.
8	P, P, P	Yellow trace shows DVALID at FPGA, green shows CLK of 1st board at J2, purple shows 12V of 1st board at J2.
9	P, P, P	Green trace shows CLK of 1st board at J2, blue shows DCLK of first board at J2.
10	3, 2, 4	Rotation of boards followed by swept covering of a few photodiodes in turn with black cloth. Reording of boards from run 9 above: note that the behaviour is similar with no output from boards 2 and 4.
11	3, 1, 4, 2	board rotation and sweep covering of photodiodes
12	3, 4, 2, 1	board rotation and sweep covering of photodiodes
13	3, 2, 1, 4	board rotation and sweep covering of photodiodes