8-bit MicrocontrollersのトピックRe: Internal pullup for input capture - 908QY4 and 9S08SH8

Internal pullup for input capture - 908QY4 and 9S08SH8

RobG — Sun, 04 May 2008 20:08:42 GMT

I understand that the internal pullup resistor is not available when using input capture function on 908QY4A. Does this also apply to the 9S08SH8? Should be a simple thing to test but I have not got the hardware yet.

Rob

Added part numbers to subject.

Message Edited by NLFSJ on 2008-05-04 11:23 PM

Re: Internal pullup for input capture - 908QY4 and 9S08SH8

fabio — Mon, 05 May 2008 19:24:47 GMT

Hi Rob G,

The new SH devices include a port interrupt circuitry which is very similar to the keyboard interrupt module. One of the differences between these two modules is the hability to control the pulling devices independently (no matter they are enabled as port interrupt sources or not).

All you have to do is to enable the respective PTxPE bit and select the desired pulling device through PTxES (1 = pull-up, 0 = pull-down).

Best regards,

Re: Internal pullup for input capture - 908QY4 and 9S08SH8

RobG — Mon, 05 May 2008 20:49:58 GMT

Thanks Fabio, that's a nice improvement over HC08.

Regards

Rob

b.t.w. Congratulations on your new book. I've had a copy for a couple of weeks. I haven't had time to do more than have a quick look but it looks to be very comprehensive and will be a great resource for beginners and more experienced designers alike.