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Watchdog that should be taken out and shot

Started by Tom Lucas September 13, 2006
Tom Lucas wrote:

> The dirty buggers - I reckon they did that on purpose. Next time I will > assume that the manual was written by an evil sadist hell-bent on > derailing my project and I shall be better prepared!
Chuckle. I suppose from this thread that you have never worked with a Japanese microcontroller before. (Sharp is not the worst - so far, NEC is the worst I've dealt with).
"larwe" <zwsdotcom@gmail.com> wrote in message 
news:1158322821.274633.205290@e3g2000cwe.googlegroups.com...
> > Tom Lucas wrote: > >> The dirty buggers - I reckon they did that on purpose. Next time I >> will >> assume that the manual was written by an evil sadist hell-bent on >> derailing my project and I shall be better prepared! > > Chuckle. I suppose from this thread that you have never worked with a > Japanese microcontroller before. (Sharp is not the worst - so far, NEC > is the worst I've dealt with).
<dons flameproof coat and puts on safety glasses> I've always liked microchip's datasheets. <runs for cover> They are written in a sensible way and I can understand them even at my most hungover. You'd have thought the Japanese would have been pretty hot on the accuracy of their documentation and I could forgive it if the language was a little "flowery" after translation. The Sharp one was actually quite well written but had suprisingly little useful information in the 900 pages of it. To be honest, most datasheets I work with are a bit ropey. I get the feeling that a summer student or new graduate has been tasked with writing them to prevent the experienced engineers being bogged down. My personal favourites are the ones which have been scanned into acrobat and then you have the fun of struggling to read them as well as trying to understand them.
Tom Lucas wrote:

> > Chuckle. I suppose from this thread that you have never worked with a > > Japanese microcontroller before. (Sharp is not the worst - so far, NEC > > is the worst I've dealt with). > > <dons flameproof coat and puts on safety glasses> > > I've always liked microchip's datasheets. > > <runs for cover>
Microchip is not a Japanese company.
> most hungover. You'd have thought the Japanese would have been pretty > hot on the accuracy of their documentation and I could forgive it if the
The problems I have with using Japanese parts [and it is not true for all vendors, or all parts] is that the English docs and tools are poor second cousins to the Japanese versions. I don't just mean instructions like "Remove the part using the tool of pointy end", I mean missing chapters, information that's TBD or inaccurate or watermarked "May not be correct for all devices", etc. I also suspect a strong thread of masochism in Japanese culture, which permeates their development process. Without exception, the proprietary tools for high-volume, small-number-of-users micros SUCK!
"larwe" <zwsdotcom@gmail.com> wrote in message 
news:1158328877.354039.32450@k70g2000cwa.googlegroups.com...
> > Tom Lucas wrote: > >> > Chuckle. I suppose from this thread that you have never worked with >> > a >> > Japanese microcontroller before. (Sharp is not the worst - so far, >> > NEC >> > is the worst I've dealt with). >> >> <dons flameproof coat and puts on safety glasses> >> >> I've always liked microchip's datasheets. >> >> <runs for cover> > > Microchip is not a Japanese company.
I know. I didn't say it was :-p
>> most hungover. You'd have thought the Japanese would have been pretty >> hot on the accuracy of their documentation and I could forgive it if >> the > > The problems I have with using Japanese parts [and it is not true for > all vendors, or all parts] is that the English docs and tools are poor > second cousins to the Japanese versions. I don't just mean > instructions > like "Remove the part using the tool of pointy end", I mean missing > chapters, information that's TBD or inaccurate or watermarked "May not > be correct for all devices", etc. > > I also suspect a strong thread of masochism in Japanese culture, which > permeates their development process. Without exception, the > proprietary > tools for high-volume, small-number-of-users micros SUCK!
Maybe they like a challenge?
"Tom Lucas" <news@REMOVE_auto_THIS_flame_TO_REPLY.clara.co.uk> wrote in 
message news:1158325736.1182.0@iris.uk.clara.net...
> "larwe" <zwsdotcom@gmail.com> wrote in message > news:1158322821.274633.205290@e3g2000cwe.googlegroups.com... >> >> Tom Lucas wrote: >> >>> The dirty buggers - I reckon they did that on purpose. Next time I will >>> assume that the manual was written by an evil sadist hell-bent on >>> derailing my project and I shall be better prepared! >> >> Chuckle. I suppose from this thread that you have never worked with a >> Japanese microcontroller before. (Sharp is not the worst - so far, NEC >> is the worst I've dealt with).
SNIP
> The Sharp one was actually quite well written but had suprisingly little > useful information in the 900 pages of it.
SNIP The section on the Color LCD controller is particularly awful. I can't point at a specific item, but I am sure there are errors. Getting a mono STN display to work was a real pain and accentuated by the sample drivers and header files in the CSPS libs. But then again, one of our Sharp contacts recommends never using the sample drivers... Scott
"Not Really Me" <scott@validatedQWERTYsoftware...XYZZYcom> wrote in 
message news:4n00iiF84nctU1@individual.net...
> > "Tom Lucas" <news@REMOVE_auto_THIS_flame_TO_REPLY.clara.co.uk> wrote > in message news:1158325736.1182.0@iris.uk.clara.net... >> "larwe" <zwsdotcom@gmail.com> wrote in message >> news:1158322821.274633.205290@e3g2000cwe.googlegroups.com... >>> >>> Tom Lucas wrote: >>> >>>> The dirty buggers - I reckon they did that on purpose. Next time I >>>> will >>>> assume that the manual was written by an evil sadist hell-bent on >>>> derailing my project and I shall be better prepared! >>> >>> Chuckle. I suppose from this thread that you have never worked with >>> a >>> Japanese microcontroller before. (Sharp is not the worst - so far, >>> NEC >>> is the worst I've dealt with). > > SNIP > >> The Sharp one was actually quite well written but had suprisingly >> little useful information in the 900 pages of it. > > SNIP > > The section on the Color LCD controller is particularly awful. I > can't point at a specific item, but I am sure there are errors. > Getting a mono STN display to work was a real pain and accentuated by > the sample drivers and header files in the CSPS libs. But then again, > one of our Sharp contacts recommends never using the sample drivers... > > Scott
I sacked that pretty quickly and paid Segger to do it. I found out many many months later that Sharp have a tool hidden deep within the website that will churn out useable header files from LCD parameters you plug into it. No idea if it works. Their example software is horrible anyway so I don't use it. It is only useful for gleaning clues such as where their programmers think the WDT is located. It irritates me that if you ask a question on the sharp mcu forum the first thing they do is tell you to use their nasty code - like I haven't already looked at that.
"Tom Lucas" <news@REMOVE_auto_THIS_flame_TO_REPLY.clara.co.uk> writes:
> "Not Really Me" <scott@validatedQWERTYsoftware...XYZZYcom> wrote > > "Tom Lucas" <news@REMOVE_auto_THIS_flame_TO_REPLY.clara.co.uk> wrote > >> "larwe" <zwsdotcom@gmail.com> wrote > >>> Tom Lucas wrote: > >>> > >>>> The dirty buggers - I reckon they did that on purpose. Next time I > >>>> will > >>>> assume that the manual was written by an evil sadist hell-bent on > >>>> derailing my project and I shall be better prepared! > >>> > >>> Chuckle. I suppose from this thread that you have never worked with > >>> a > >>> Japanese microcontroller before. (Sharp is not the worst - so far, > >>> NEC > >>> is the worst I've dealt with). > > > > SNIP > > > >> The Sharp one was actually quite well written but had suprisingly > >> little useful information in the 900 pages of it. > > > > SNIP > > > > The section on the Color LCD controller is particularly awful. I > > can't point at a specific item, but I am sure there are errors. > > Getting a mono STN display to work was a real pain and accentuated by > > the sample drivers and header files in the CSPS libs. But then again, > > one of our Sharp contacts recommends never using the sample drivers... > > > > Scott > > I sacked that pretty quickly and paid Segger to do it. I found out many > many months later that Sharp have a tool hidden deep within the website > that will churn out useable header files from LCD parameters you plug > into it. No idea if it works. > > Their example software is horrible anyway so I don't use it. It is only > useful for gleaning clues such as where their programmers think the WDT > is located. It irritates me that if you ask a question on the sharp mcu > forum the first thing they do is tell you to use their nasty code - like > I haven't already looked at that.
We once did battle with a U.S. manufacturer of a very heavy-duty video board about documentation, etc. We wanted to activate the board to handle 875-line video and wanted some hints as to what values to use for the many parameters the board had. The "tech support" answer was "use the C library routines provided". When I would point out that we didn't have a C compiler for the target computer (many years ago) and the library source files provided were missing the last sector of each, a long silence followed. The documentation was even worse. One page of the manual gave three different "answers" to what to do about some particular thing. When asked about which of the three answers was correct, the reply was "none of the above"! When we complained about the sorry state of the docu- mentation, we were told they didn't want to talk to us anymore. I've always been impressed by the person who exhibited the patience of Job in twiddling the 30 or so parameters until the board worked.
"Tom Lucas" <news@REMOVE_auto_THIS_flame_TO_REPLY.clara.co.uk> wrote in
message news:1158232347.43487.0@despina.uk.clara.net...
> "Tom Lucas" <news@REMOVE_auto_THIS_flame_TO_REPLY.clara.co.uk> wrote in > message news:1158161579.6562.0@proxy00.news.clara.net... > > I've been trying to implement the watchdog timer on my Sharp79524 and > > it appears that the mutt is sleeping on the job! > > > > I believe I have it set up to trigger after about 3s of inactivity but > > it doesn't seem to reset the system at all. > > Problem Solved! > > It turns out that the address of the watchdog register is actually > 0xFFFE3000 instead of the 0xFFFC3000 that is shown in the user guide. > This is a case where RTFM has caused the problem! > > D'oh!
I'm sorry I didn't report the addresses that I poked when trying this out. Not that it would have helped much since it (correctly) says FFFE2000 in my Sharp 754xx manual. It might have prompted you to look again though. But why use different addresses on different chips? Wrong information is worse than no information at all. At least in the latter case you know that you don't know. Peter
"Peter Dickerson" <first{dot}surname@tesco.net> wrote in message 
news:v7uPg.28728$SH2.19588@newsfe4-gui.ntli.net...
> "Tom Lucas" <news@REMOVE_auto_THIS_flame_TO_REPLY.clara.co.uk> wrote > in > message news:1158232347.43487.0@despina.uk.clara.net... >> "Tom Lucas" <news@REMOVE_auto_THIS_flame_TO_REPLY.clara.co.uk> wrote >> in >> message news:1158161579.6562.0@proxy00.news.clara.net... >> > I've been trying to implement the watchdog timer on my Sharp79524 >> > and >> > it appears that the mutt is sleeping on the job! >> > >> > I believe I have it set up to trigger after about 3s of inactivity >> > but >> > it doesn't seem to reset the system at all. >> >> Problem Solved! >> >> It turns out that the address of the watchdog register is actually >> 0xFFFE3000 instead of the 0xFFFC3000 that is shown in the user guide. >> This is a case where RTFM has caused the problem! >> >> D'oh! > > I'm sorry I didn't report the addresses that I poked when trying this > out. > Not that it would have helped much since it (correctly) says FFFE2000 > in my > Sharp 754xx manual. It might have prompted you to look again though. > But why > use different addresses on different chips? > > Wrong information is worse than no information at all. At least in the > latter case you know that you don't know.
If we wanted it to be easy we wouldn't have become engineers :-D
Everett M. Greene wrote:

> I've always been impressed by the person who exhibited > the patience of Job in twiddling the 30 or so parameters > until the board worked.
I've been that person. When I was getting the first Digi-Frame up and running, I had no complete documentation for the VGA controller. A lot of it was something like this: Document A: For more details on this, see Document B where it is explained in detail. Document B: This information has been moved to Document A. So I used their demo kit to dump out all the CRTC and sequencer registers (documented and undocumented) for a standard 640x480 VGA mode. I also dumped out all the documented nonstandard registers. Then I put a bunch of pushbuttons on my target system and wrote a program that would let me play with all the parameters. When I got a stable picture on my LCD, I hit the "dump" button and got a header file... :)