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Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-counter')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-counter | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter index 1417c4272c6c..dc3b3a5c876b 100644 --- a/Documentation/ABI/testing/sysfs-bus-counter +++ b/Documentation/ABI/testing/sysfs-bus-counter @@ -90,6 +90,60 @@ Description: counter does not freeze at the boundary points, but counts continuously throughout. + interrupt on terminal count: + The output signal is initially low, and will remain low + until the counter reaches zero. The output signal then + goes high and remains high until a new preset value is + set. + + hardware retriggerable one-shot: + The output signal is initially high. The output signal + will go low by a trigger input signal, and will remain + low until the counter reaches zero. The output will then + go high and remain high until the next trigger. A + trigger results in loading the counter to the preset + value and setting the output signal low, thus starting + the one-shot pulse. + + rate generator: + The output signal is initially high. When the counter + has decremented to 1, the output signal goes low for one + clock pulse. The output signal then goes high again, the + counter is reloaded to the preset value, and the process + repeats in a periodic manner as such. + + square wave mode: + The output signal is initially high. + + If the initial count is even, the counter is decremented + by two on succeeding clock pulses. When the count + expires, the output signal changes value and the + counter is reloaded to the preset value. The process + repeats in periodic manner as such. + + If the initial count is odd, the initial count minus one + (an even number) is loaded and then is decremented by + two on succeeding clock pulses. One clock pulse after + the count expires, the output signal goes low and the + counter is reloaded to the preset value minus one. + Succeeding clock pulses decrement the count by two. When + the count expires, the output goes high again and the + counter is reloaded to the preset value minus one. The + process repeats in a periodic manner as such. + + software triggered strobe: + The output signal is initially high. When the count + expires, the output will go low for one clock pulse and + then go high again. The counting sequence is "triggered" + by setting the preset value. + + hardware triggered strobe: + The output signal is initially high. Counting is started + by a trigger input signal. When the count expires, the + output signal will go low for one clock pulse and then + go high again. A trigger results in loading the counter + to the preset value. + What: /sys/bus/counter/devices/counterX/countY/count_mode_available What: /sys/bus/counter/devices/counterX/countY/error_noise_available What: /sys/bus/counter/devices/counterX/countY/function_available |