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73 lines
2.1 KiB
Plaintext
73 lines
2.1 KiB
Plaintext
ubbctl - Control UBB signals
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============================
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ubbctl queries the state of UBB signals and allows the user to change
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them. It can run in parallel with any other UBB users.
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Querying
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--------
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To query the UBB signals, run
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# ubbctl
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This will display something like this:
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nPWR=1 DAT2=F1 DAT3=F1 CMD=F1 CLK=Z1 DAT0=1 DAT1=0
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"0" means that the pin is driven low. "1" means that is it driven
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high. If the pin reads back as something different than what it is
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set to, this is indicated as "0!1" (pin is shorted to VDD) or "1!0"
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(pin is shorted to ground).
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"Z0" and "Z1" means that the pin is an input without internal
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pull-up (note however that all pins but nPWR and CLK) have external
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10 kOhm pull-ups) and that it reads back a low or high,
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respectively.
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"R0" and "R1" are like "Z0" and "Z1", except that the internal
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pull-up is enabled.
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"F0" and "F1" indicate that the pin configured as a function (i.e.,
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for the MMC controller) and does not operate as GPIO. If the second
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function of the pin is selected, "Fb..." is shown instead of "F...".
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"I..." indicates that the pin is configured as an interrupt. The
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next letter defines the type of interrupt, "r" for rising edge,
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"f" for falling edge, "h" for high level, and "l" for low level. If
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the pull-up is enabled, ubbctl adds an "R". Finally, it shows the
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pin status. E.g., "IfR1" would be an interrupt triggering on the
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falling edge, with pull-up enabled, and currently inactive.
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ubbctl can run in continuous mode, in which it updates the status
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regularly (currently every 200 ms):
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# ubbctl -c
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To exit continuous mode kill the process, e.g., which Ctrl-C.
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Setting
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-------
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ubbctl can change the configuration of the UBB pins. The syntax is
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the same as the one used for the status display except that there
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are no readback values. E.g., nPWR=1 would disable power, CLK=R
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would configure CLK as input with pull-up, etc.
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A pin can be changed several times. For example, if the idle state
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of DAT0 is 0
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# ubbctl dat0=0
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then
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# ubbctl dat0=1 dat0=0
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would send a short positive pulse.
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ubbctl also recognizes the keywords ON and OFF to control power to
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the 8:10 interface. They're synonymous to nPWR=0 and nPWR=1,
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respectively.
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