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Re: wrong read : readbits
----- Original Message -----
From: "Sébastien LICHT" <firstname.lastname@example.org>
Sent: Thursday, July 22, 2004 4:59 PM
Subject: wrong read : readbits
> after setting some bits with
> ioctl(fd, _IO(ETRAXGPIO_IOCTYPE, IO_CLRBITS ), 1 << bit);
> ioctl(fd, _IO(ETRAXGPIO_IOCTYPE, IO_SETBITS ), 1 << bit);
> (where "bit" is 1,2,3,4 or 5) ,
> the "readbits" command seems to be locked : "0" bits can change to "1"
> but never return to "0" (i forced the pins to GND but no effects)
> after reset , the command seems to rework perfectly
Not sure what you are trying to do.
Please not that bit 1,2,3,4 and 5 on gpiog are both input and output at
the same time but on different pins.
You control the output with IO_SETBITS and IO_CLRBITS but that doesn't
effect the result when reading the pins (unless you connect them together)
> I don't understand, because i have used only the IO_CLRBITS or IO_SETBITS
> with 1 to 5 for writting
> and i looked for bits 8-15 , i don't touch them
> i've also tried to place :
> data = mask = 0xFF << 8;
> ioctl(fd, _IO(ETRAXGPIO_IOCTYPE, IO_SETGET_INPUT), &mask);
> but nothing
That command sets G8-15 to input and updates mask with all bits that
can be used as inputs.
> thanks for help