Post by thread:[PIC]: ER mode PIC16F628

Hi, all:- There does not seem to be any typical or otherwise figures on clock frequency vs. DC bias resistor on this part. The datasheet (DS40300B-page 98) refers to the "Electrical Specification" section, which doesn't seem to have anything in it, only min/max frequency numbers with no indication of what resistances would be required to produce those frequencies. Anyone have even one data point for this? Eg. with a 100K resistor, I get XX MHz clock. (There are also a couple of mistakes/omissions on the Pinout description overview (page 11), none of which have made their way to the errata yet.) Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" spam_OUTspeffTakeThisOuTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com -- http://www.piclist.com hint: To leave the PICList .....piclist-unsubscribe-requestKILLspam@spam@mitvma.mit.edu

> Anyone have even one data point for this? Eg. with a 100K > resistor, I get XX MHz clock. http://www.voti.nl/fader/ As noted on the page, I got the info from the PIClist :) Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestKILLspammitvma.mit.edu

> There does not seem to be any typical or otherwise figures on > clock frequency vs. DC bias resistor on this part. The datasheet > (DS40300B-page 98) refers to the "Electrical Specification" > section, which doesn't seem to have anything in it, only min/max > frequency numbers with no indication of what resistances would > be required to produce those frequencies. > > Anyone have even one data point for this? Eg. with a 100K > resistor, I get XX MHz clock. My post, 16th Jan 2002 [PIC]: 16f628 external resistor frequency These are practical measurements for 16F628-04 R Clkout * 4 2k7 9.40MHz 3k3 9.35 4k7 9.23 10k 8.44 22k 5.65 39k 3.50 100k 1.52 220k 0.75 MHz 470k 0.393 1M 0.192 1M5 0.124 2M2 85,600 Hz 5M6 36,400 12M 16,400 -- http://www.piclist.com hint: To leave the PICList .....piclist-unsubscribe-requestKILLspam.....mitvma.mit.edu

At 10:54 AM 12/3/02 +1300, you wrote: Thanks a bunch Jinx, and Wouter for mentioning it. Just what's required. ;-) {Quote hidden}>These are practical measurements for 16F628-04 > > R Clkout * 4 > > 2k7 9.40MHz > 3k3 9.35 > 4k7 9.23 > 10k 8.44 > 22k 5.65 > 39k 3.50 >100k 1.52 >220k 0.75 MHz >470k 0.393 > 1M 0.192 >1M5 0.124 >2M2 85,600 Hz >5M6 36,400 >12M 16,400 > Spehro Pefhany --"it's the network..." "The Journey is the reward" EraseMEspeffspam_OUTTakeThisOuTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestspam_OUTmitvma.mit.edu

>(There are also a couple of mistakes/omissions on the Pinout >description overview (page 11), none of which have made their >way to the errata yet.) Such as? I'm using the '627 and aside from the published Errata I had no problems. I'm using INTRC mode with RA6 I/O. This chip is just a couple years late for me - we had requested it from MCHIP about 4 years ago, and ended up designing around a '558 with some lower throughput. Andy -- http://www.piclist.com hint: To leave the PICList @spam@piclist-unsubscribe-requestKILLspammitvma.mit.edu

At 06:41 PM 12/2/02 -0500, you wrote: > >(There are also a couple of mistakes/omissions on the Pinout > >description overview (page 11), none of which have made their > >way to the errata yet.) > >Such as? Probably would only catch newbies, but since a lot of such use this chip first, I'll mention them: 1) The fact RA4 is open-drain only when used as an output is not mentioned on Page 11, whereas it is on, say the 16F876. 16F62x: Bi-directional I/O port/Can be configured as T0CKI/comparator output 16F87x: RA4 can also be the clock input to the Timer0 module. Output is open drain type. 2) RA6/OSC2/CLKOUT description says: Bi-directional I/O port/Oscillator crystal output. Connects to crystal or resonator in crystal oscillator mode. In ER mode, OSC2 pin outputs CLKOUT which has 1/4 the frequency of OSC1, and denotes the instruction cycle rate. When this is actually optional behavior, so RA6 can be used for general purpose I/O while using ER mode (there are two ER modes, with and without clock/4 output on RA6). Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" KILLspamspeffKILLspaminterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu

>1) The fact RA4 is open-drain only when used as an output is not > mentioned on Page 11, whereas it is on, say the 16F876. > > 16F62x: Bi-directional I/O port/Can be configured as >T0CKI/comparator output > > 16F87x: RA4 can also be the clock input to the Timer0 module. >Output is open drain type. > OK, but that's pretty much a given with PICs. RA4 = O/C. {Quote hidden}>2) RA6/OSC2/CLKOUT description says: > > Bi-directional I/O port/Oscillator crystal output. Connects to >crystal or resonator in crystal > oscillator mode. In ER mode, OSC2 pin outputs CLKOUT which has 1/4 >the frequency > of OSC1, and denotes the instruction cycle rate. > > When this is actually optional behavior, so RA6 can be used for >general > purpose I/O while using ER mode (there are two ER modes, with and > without clock/4 output on RA6). It can also be that way for two IRC modes. Thanks for clearing it up. I thought it was something new. Andy -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestspamBeGonemitvma.mit.edu