FILTER - Filter¶
The filter block has two different modes of operation: Difference and Average. They both work by latching the values on the input and performing an operation comparing to the current value.
Fields¶
| Name | Type | Description |
|---|---|---|
| ENABLE | bit_mux | Enable event |
| TRIG | bit_mux | Trigger event |
| INP | pos_mux | Input data |
| MODE | param enum | Select operation mode
0 difference
1 average
|
| READY | bit_out | Output Ready |
| OUT | pos_out | Output data |
| HEALTH | read enum | Error
0 OK
1 Accumulator overflow
2 Divider retrigger
|
Difference¶
The difference operation works by latching the value on the input on the rising edge of the Enable signal. On a rising edge of the trigger signal the output is given as the the current input value minus the latched value.
(Source code, png, hires.png, pdf)
After the operation, the latched value is updated to be the current value on the input.
(Source code, png, hires.png, pdf)
The operation continues to work if the current value is less than the latched value: a negative result is outputted
(Source code, png, hires.png, pdf)
Average¶
The average function appends a sum value on each clock pulse. When a trigger signal is received it divides the summed value by the number of clock pulses that have passed.
(Source code, png, hires.png, pdf)
(Source code, png, hires.png, pdf)
(Source code, png, hires.png, pdf)
If a calculation is triggered before the calculation is ready, the system will show an error on the HEALTH output and will then need to be re-enabled before another calculation can be sent.
(Source code, png, hires.png, pdf)
(Source code, png, hires.png, pdf)
