Flashy Clock - Yet another DEV board

[PhilC]

Never had one until today. I can always try one of your v1 5 boosters on it?

[exxos]

Never had one until today. I can always try one of your c1 5 boosters on it?

I think I tried it in the V2.2.. was probably last year when Peter was working on the TOS104 mods for the 010.. So probably mentioned on the forum at some point.

[PhilC]

12mhz seems to be the fastest I can find in DIL64 and 20mhz in PGA.

[PaulJ]

I've been working on a C app to deal with clock functionality that at this point parrots Exxos's stos app clock selections. Been some what of a pain in the arse. I'm on my 3rd C development system. Tried Lattice which I had been using but getting into supervisor mode had issues and the debugger was nothing to brag about. Went to MWC which used to be my goto C development system but it also had issues. So just out of desperation I gave Pure-C a try and it works much better for me that the other two and the debugger is pretty good.

The clock chip DS12885S and its data sheet are some what unfriendly. Two eight bit registers aligned on word boundaries. You write the first register with register number you want to access and then write or read it from the second address. When you read the data sheet they don't discuss the two registers and basically go on as if all registers are all memory mapped. At first I set up the second register to access register 10 that contained UIP bit which tells you when the chip is not in a update cycle or won't be for another 250 USEC's so you can inhibit updates when you make changes. I ASSUMED since there was no description that once you selected the 2nd register via the first that it would remain selected until you changed it. WRONG.. It appears there is a hardware cycle where you must write the register you want and access the second register. Thats it. If you attempt to deviate the chip locks up and the lockup survives a repower or reset. Had to take the battery out and wait to clear the hang. I can now reliably access the chip and were getting along fine.

Just when things were going good the lights on the Eiffel remain on and its dead to the world!!. Had to pull the one of the remake board. This is the second time the pic has croaked. I believe there's a design issue or this one board has some sorta gremlin. Guess I have to take some time and burn a new pic.

So I'm finally to the point where I can move forward. Now that I can reliably read and write the registers it just a matter of manipulating the bits. So we are making progress.

[exxos]

Yeah you have to set the address each time. I noted that on the forum or in the code somewhere.. I thought you could just set a address and just read from it all the time but it screws up.

Reading and writing to the chip is a bit confusing because of its multiplexed bus. Its annoying as you just can't set the address with the CPU and read it like normal. I considered ditching the chip because of that originally .

Not sure why you need supervisor mode though ? Just normal deek and doke to the rtc address is all that's needed. I'm using hisoft basic BTW not stos ... But peek becomes speek for supervisor peek, I don't think I use it anywhere in that code. I think in had to use it a couple of times in GB6 though somewhere.

In any case, you should be almost able to copy my code right over to asm. It doesn't really do much other than variables and peek and poke type stuff. Granted its not programmed in the best of ways, but it gets the job done at least.

[exxos]

Is a lot of info here https://www.exxosforum.co.uk/forum/viewt ... 537#p23537

[PaulJ]

Interesting read... I have to say I have encountered a lot of the same issues. Its been my experience over the years that the data sheets in general suck. If there's a short coming it the device, designers tend to gloss over those parts in the data sheet. A lot of the chip designers are satisfied when the device does what they intended no matter how ugly it is to use the chip.

I spent some time looking at your basic program and have gleened a lot on how you have accessed the chip. Pretty painful in basic it appears where using C lends itself to a memory mapped env. It looks like you had to jump through some hoops even using strings for a lot of the situations. Really have never used basic or stos so I assumed it was a stos app since you speak highly of it.

[exxos]

Interesting read... I have to say I have encountered a lot of the same issues. Its been my experience over the years that the data sheets in general suck. If there's a short coming it the device, designers tend to gloss over those parts in the data sheet. A lot of the chip designers are satisfied when the device does what they intended no matter how ugly it is to use the chip.

Yes your right, datasheets do generally suck. In my more PIC and amp days, there would be millions of pages of all specs, other than what voltage the thing is supposed to run on. Really is amazing omissions and typos in those things.

I spent some time looking at your basic program and have gleened a lot on how you have accessed the chip. Pretty painful in basic it appears where using C lends itself to a memory mapped env. It looks like you had to jump through some hoops even using strings for a lot of the situations. Really have never used basic or stos so I assumed it was a stos app since you speak highly of it.

I did do some stuff in STOS.. but later went for hisoft basic to get more a "gem app". STOS had really nice bit functions to change a bit easily in a variable.. hisoft had nothing. I had to bodge up my own routines to do it. Converting to a string to use MID$ to swap bits was the quickest way I could think of doing it.. but then I had to convert it back to a number again.. So it got pretty messy very quick. I would assume there would be better bit manipulations in assembly ?

[PaulJ]

Yes your right, datasheets do generally suck. In my more PIC and amp days, there would be millions of pages of all specs, other than what voltage the thing is supposed to run on. Really is amazing omissions and typos in those things.

When I worked at Motorola we were going to use a star core for our Set Top Box until the data sheet and irata arrived. Thing was the size of a NYC phone book mostly consisting of issues. Nothing a software engineer and 20 years of time couldn't work around.

I did do some stuff in STOS.. but later went for hisoft basic to get more a "gem app". STOS had really nice bit functions to change a bit easily in a variable.. hisoft had nothing. I had to bodge up my own routines to do it. Converting to a string to use MID$ to swap bits was the quickest way I could think of doing it.. but then I had to convert it back to a number again.. So it got pretty messy very quick. I would assume there would be better bit manipulations in assembly ?

No matter what tool one uses there is always something another tool is better at. Still believe when God sits down to create an app he uses C and VI!! :) :) :)

[Icky]

Received some of these in the post today

IMG_4243.jpg

Looking nice and tiny over the CPU socket

IMG_4240.jpg

On top of the previous board for comparison

IMG_4244.jpg