Get a DS89C450 running...

[danyat]

ds89c450

Hi!

Does anybody ever tried somthing with a DS89C4[3/4/5]0 Microcontroller? Ive 2 of them and tried to communicate with the ROM-Loader (which should be onchip) - but without success.

Ive set it up on a problem-board, with a xtal (12mhz) and pulled the rst high, the /EA and /PSEN low (as mentioned in the datasheet).
A max232 to the UART0 (RXD0, TXD0) and a PC with serial-terminal-prog on the other side. The datasheet says, that the Micro should autodetect the baud-rate (upon a <CR>) and than return a initial Banner (some ascii text) to the terminalprog... But nothing happens. The xtal is running (oszilloscope).

What may be wrong? Any idea?
Ive no paralell-programmer to test any code on it...

Thx
Daniel

 

[FoxyRick]

89c450 programming

If this is too obvious and you've checked already, sorry

Make sure the serial port is set correctly in the terminal prog, especially check that handshaking is turned off. I have a habit of forgetting this

I'll watch this with interest, as I've just got two '450's myself and haven't had chance to play with them yet.

Cheers,
FoxyRick.

 

[danyat]

89c450 clock configuration

Hi!

> I've just got two '450's myself
Two? Samples i guess?!? Ive also get them as samples.

Thx for the hint - i often forget to check these things, but not this time... Ive used differnt terminalprograms on different computers with different platforms (telnet on xp, minicom on linux).

If probed the rs232 signal after the pc and the ttl-level rs232 after the max. Its okay. but ther is no answer from the 89c450 - even no ttl-level change on txd...

Is it possible that the device isnt working at all? (because its a sample)
i dont think, that i ve destroied it... ive even payed attention to esd (alwas grounded myself).

What ill try next is to use different (slower and maybe faster) xtals...

cu
Daniel

 

[FoxyRick]

ds89c450

I've just checked the formual for working out the auto-baud detection. A 12MHz crystal only gives a close-enough match at 1200, 2400 and 4800 baud. Have you tried one of these? If not, that may be the problem.

An 11.0592MHz cryatal will give a baud match at 57600.

Hope this helps,

FoxyRick.

 

[danyat]

ds89c450 user guide

Wuha! Gotcha!!

Thank you - it works!

I never thought, that ther may be a problem with Bauds> 9600. Iam used to AT AVRs and ther i never had matching-probs with bauds up to 115200 at 8Mhz.

But again: thx!!
Daniel

 

[FoxyRick]

ds89c450 clock configuration

Excellent

Do you have Maxim's High Speed Flash Guide for these parts? It has information not in the datasheets (typical!) including how the baud detection works.

**broken link removed**

Glad you got it working.

Cheers,
FoxyRick.

 

[glenjoy]

ds89 450 8051

Check my website: **broken link removed**

 

[Analyzer]

how to program dallas semiconductor max233

Hi,

I also have a dozen of this MCU but i never used mcu other than Pic.So i need to have some info.Especially e-books for DS89C420.What is its simplest configuration?

Analyzer

 

[glenjoy]

how to load program ds89c450

Check my website above, it has schematic and the configs, you cn build it around a breadboard, btw read also the USER GUIDE at Maxim's Website.

 

[silvio]

ds89c450 uart timer

Hi Daniel,

Sometimes it's usefull to read the errata REV A1 too. You never know what else can discover.
I don't know if the 89C450 inherits some old bugs from 89C420:

The auto-baud routine of the bootstrap loader does not always function reliably (observed as garbled
information instead of loader banner). Functionality is better at lower baud rates. Experiments show
that the maximum reliable baud rate for any given crystal frequency is given by the equation:
fOSC / 1152 = Max Baud

You can read all errata sheets on Maxim's site:

h**p://pdfserv.maxim-ic.com/errata/89C420A1.pdf
h**p://pdfserv.maxim-ic.com/errata/89C420A2.pdf
h**p://pdfserv.maxim-ic.com/errata/89C430A2.pdf
h**p://pdfserv.maxim-ic.com/errata/89C430A3.pdf
h**p://pdfserv.maxim-ic.com/errata/89C440A2.pdf
h**p://pdfserv.maxim-ic.com/errata/89C440A3.pdf
h**p://pdfserv.maxim-ic.com/errata/89C450A2.pdf
h**p://pdfserv.maxim-ic.com/errata/89C450A3.pdf

 

[danyat]

ds89c450 uart timer tmod

Yep... thx for your post... ive read the errata already before... in my case (now i use a 24Mhz xtal) the maxBaud (acc. to this formula) would be ~20kbaud. But the matching to one of the timer-reloads was the problem. I dont know, why they had used only a few possible reloadvalues (acc. to the datasheet), so that the matching is only given for some baudrates...

I use now 2400 Baud (xtal: 24Mhz), and it works - slow, but it works...

Thx again,
bye
Daniel

 

[sekafree]

c program example for ds89c450

Hello,

I got two ds89C400.
But when it is time to try them, ouch very small pins 8O

So could you tell me how you test these kind of very small controllers ? Do you use a sort of zif socket, or are you able to mount them on a board ?

Any help or information is welcome

Thanks a lot!

 

[Kripton2035]

ds89c450 serial example

they talk about 89c450 which is available as DIP package...
the 89c400 you have is only available as tqfp package which is very very very small pins...
but this 89c400 has unique tcpip features in rom, not the others..

so you must choose between tcpip - small pins and no tcpip and dip package..

 

[glenjoy]

ds89c450 isp circuit

Use 11.0592 Mhz crystal, this speed can provide with most of the baud rates.

 

[danyat]

ds89c450 programmer

I have some pics of my first running DS89C450 attached. It is a 8-Bit MCU@24Mhz driven blinking Led . how usefull!

So, now i can study the mc51 architekture a bit... iam normally used to the AVR (Atmel's 8bit riscs) - But ive heard a bit of 8051 at my previous school...

But thx again to the forum - without you, my led wouldnt flash that way!

 

[Apoxioman]

parallel programming ds89c450

I'm trying to enter 89c420 bootloader mode with Xtal 18.432 MHz, but the same problem..
Baund rate 19 200 // Osc./(192*(0xFF-0xFA))
I know that 18432000/1152 < 19200, but what must happen?
If bootloader don't detect autoboud, is there any garbled string?

PS: REVISION A1 ERRATA
The signal PSEN is driven by a strong pullup internally, and the component used to pull it down to
enter loader mode must be capable of sinking 100mA of current to ground.

If this is true, how can you pull it down with 74ls125 or 74ls367 when max LOW Level Output Current = 24 mA ... ?

 

[glenjoy]

89c450 rs232

I think it is your crystal that has the problem, I've been using the 367 for the DS89 series and no problem encountered.

 

[glenjoy]

ds89c450 bootloader

Another, have you check the version of your chip? I think it is A2 now so you don't have to worry anymore about the problem in A1 because it had been corrected by the A2 design release. Do read the datasheet or the revision sheet before posting anything.

 

[Apoxioman]

ds89c450 bootloader schematic

You're right GLENJOY... it's A2
I will change it (Xtal).
Do you thing it is possible to implement PCI v2.2 with DS89 ?
I need 16,75 Mhz clock for RTL8139 , which I think to get directly from Xtal, and... very very optimized source
I get this MCU because of "instruction/cycle" time ability

 

[pisoiu]

ds89c450 one wire

Some hints (from experience). Use only crystals which offer exact baud rates. Differences in calculated baudrate more/less than 5% compared with standard baudrates will cause the autobaud algorythm to fail in most cases. Also, the flash programming consumes some energy, so if your power supply is not very capable, the flash programming will fail, randomly. Use a high value/low esr electrolytic cap near cpu (470..1000uF). I cursed all my ancestors for a whole week until I realised I have to put this cap...I wasn't even smart enough to take a look at the power lines with the oscilloscope.

/pisoiu