Root/ubbctl/README

1ubbctl - Control UBB signals
2============================
3
4ubbctl queries the state of UBB signals and allows the user to change
5them. It can run in parallel with any other UBB users.
6
7
8Querying
9--------
10
11To query the UBB signals, run
12
13# ubbctl
14
15This will display something like this:
16
17nPWR=1 DAT2=F1 DAT3=F1 CMD=F1 CLK=Z1 DAT0=1 DAT1=0
18
19"0" means that the pin is driven low. "1" means that is it driven
20high. If the pin reads back as something different than what it is
21set to, this is indicated as "0!1" (pin is shorted to VDD) or "1!0"
22(pin is shorted to ground).
23
24"Z0" and "Z1" means that the pin is an input without internal
25pull-up (note however that all pins but nPWR and CLK) have external
2610 kOhm pull-ups) and that it reads back a low or high,
27respectively.
28
29"R0" and "R1" are like "Z0" and "Z1", except that the internal
30pull-up is enabled.
31
32"F0" and "F1" indicate that the pin configured as a function (i.e.,
33for the MMC controller) and does not operate as GPIO. If the second
34function of the pin is selected, "Fb..." is shown instead of "F...".
35
36"I..." indicates that the pin is configured as an interrupt. The
37next letter defines the type of interrupt, "r" for rising edge,
38"f" for falling edge, "h" for high level, and "l" for low level. If
39the pull-up is enabled, ubbctl adds an "R". Finally, it shows the
40pin status. E.g., "IfR1" would be an interrupt triggering on the
41falling edge, with pull-up enabled, and currently inactive.
42
43ubbctl can run in continuous mode, in which it updates the status
44regularly (currently every 200 ms):
45
46# ubbctl -c
47
48To exit continuous mode kill the process, e.g., which Ctrl-C.
49
50
51Setting
52-------
53
54ubbctl can change the configuration of the UBB pins. The syntax is
55the same as the one used for the status display except that there
56are no readback values. E.g., nPWR=1 would disable power, CLK=R
57would configure CLK as input with pull-up, etc.
58
59A pin can be changed several times. For example, if the idle state
60of DAT0 is 0
61
62# ubbctl dat0=0
63
64then
65
66# ubbctl dat0=1 dat0=0
67
68would send a short positive pulse.
69
70ubbctl also recognizes the keywords ON and OFF to control power to
71the 8:10 interface. They're synonymous to nPWR=0 and nPWR=1,
72respectively.
73

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