Greetings > -----Original Message----- > From: andy pugh [mailto:bodge...@gmail.com] > Sent: 12 November 2015 22:07 > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] 5i25 miss-behaving
> On 12 November 2015 at 21:44, Gene Heskett <ghesk...@wdtv.com> wrote: >>> Checking the status in showconfig, it (gpio.003) is an input. And I >>> do not believe I have a separate pullup on the line, that card is >>> AFAIK, doing that 3.3 volts. Any pullups I would have installed >>> would have been to the 5 volt rail. > Are the 5i25 inputs 5V tolerant? -- > atp It all depends! From 5i25 manual 5V I/O TOLERANCE The FPGA used on the 5I25 has a 4V absolute maximum input voltage specification. To allow interfacing with 5V inputs, the 5I25 has bus switches on all I/O pins. The bus switches work by turning off when the input voltage exceeds a preset threshold. The 5V I/O tolerance option is the default and should normally be left enabled. For high speed applications where only 3.3V maximum signals are present and overshoot clamping is desired, the 5V I/O tolerance option can be disabled. W3 controls the 5V I/O tolerance option. When W3 is on the default UP position, 5V tolerance mode is enabled. When W3 is in the DOWN position, 5V tolerance mode is disabled. Note that W3 controls 5V tolerance on both P2 and P3 I/O connectors. W3 also selects the pull-up resistor voltage, When 5V I/O tolerance mode is selected, the I/O pull-up resistors are powered from 5V. When 5V I/O tolerance mode is disabled, the I/O pull-up resistors are powered with 3.3V. John Prentice ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
