On Fri, Mar 11, 2011 at 12:54 AM, Bob Blick wrote: > > > On Fri, 11 Mar 2011 00:40 +0530, "Manu Abraham" =A0wrote: > >> >> Just to make myself feel a bit safer: even in those cases, where /MCLR >> is not floated, does it hurt if there is the regular 10k pullup ? > > When the ICD2 turns on VPP the higher voltage will cause current to flow > through the resistor into your positive supply, with a 10K resistor > it'll be almost a milliamp. If there is not enough load to absorb it, it > can raise your power supply voltage. If you are powering the target off > the ICD2 then you are probably OK, or if you have enough load on the > target's power supply. > > You can use higher value resistors, 47K is fine. Then there is less > current and less chance anything will happen. The 18f4550 datasheet (39632c) Section:4.3 states that R < 40k is recommended to make sure that the voltage drop across R does not violate the device's electrical specification. (If this makes things any better, I am additionally using Vdd=3D3.3v) So, with a 47k resistor there is some chance that the device might not be Reset properly in some cases, when not using the debugger (ie in standalone mode) ? Thanks, Manu --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .