Messages

try www.digikey.com

>I noticed that sometimes the clock frequency was 10MHz depending on
>how I bypassed the clk1 & clk2 pins
>wrong forum. Oh well, you used an overtone crystal instead of a f>undamental crystal, that's why.

If you leave a cap on pin XTAL2 but remove the cap on XTAL1 you
will not get a resonance of 30M, put the cap on XTAL1 and get 10M.

I was using a 30MHz crystal and 2 27pf capacitors on a 80C51 XA.
I noticed that sometimes the clock frequency was 10MHz depending on
how I bypassed the clk1 & clk2 pins.  Replacing a 2 pin 30Mhz crystal with a 30MHz crystal oscillator (4 pin) madequite a big difference in baud rate.
 I used to get no higher than 38,400 with just a crystal and two 27pf capacitors.  But now I can send and receive at 115200. The quality of the
clock signal makes a difference.

Hi,
     I figured the problem out. The reset circuit has to be different than for
     the P89C668.  For the P89C668 I had a 10uf cap and push button
     switch in parallel , one side to 5V and the other side to RST (pin 10).
     I also had a 10K resistor and signal diode in parallel , one side to
     RST and the other side to ground.  This was a design I obtained from
     my work with the P89C51RD2BN.

     What works now is simply a 10k resistor from 5v to RST and a push
     button switch and 10uf cap in parallel , one side to RST and the other
     side to ground. The upper limit for baud rate is 19,200 using a 30MHz
     crystal.  I am actually using a flash programming tool I wrote using
     Tcl/Tk and C. It works as your FlashMagic program does but I needed
     something for Linux. You might want to push Philips to change their
     data sheets, they still recommend that people download WinISP.

     Thanks

hi,
    I have had good results with the P89C668, P89C51RD2BN, and
    P89C51RD2HBP. Lately I have tired the XA part and it does not
    appear to echo the initial character. The pinout of the P89C668
    and XAG49 are the same. The philips data sheet says to connect
    EA/WAIT(pin 35) to Vdd and leave ALE(pin 33)open. When I apply
    reset  I see the ALE pin pulse from high to low to high again. I see
    the clock out pin XTAL2 (pin 20) at 20MHz. But I think the device is
    locked up. There is one difference though, the data sheet says that
    a lower case "f" is to be sent. The three parts I have used before
    require a upper case "U". I also know about the EA/WAIT pin
    used for external access. But the data sheet says to tie it high
    for internal access only. I've been visiting this forum for a while
    and not much gets asked about the XA part. Any ideas.

The Philips application note is AN95068
It is titled "C routines for the PCx8584"

You might also want application note AN96040 and
data sheet for the PCF8584 I2C bus controller.

Philips has released a i2c driver that you could adapt to your case.
I wrote my own driver for a P89C668 device.  You won't be able to
get above a rate of about 70k.

Competitors products do not require a "NoTouch" bandage.
Also, I have heard comments in this discussion group about a simple
call to a Philips FE and they will re-program your devices. That is not
true. The local person in San Jose area (Lisa M Williams) will just tell
you that you need a parallel programmer.

Applications engineer from philips suggested this for safety. Been using
a 4.7k pullup for about a year now,  no problems. Very useful.

You have not been to many Embedded Systems conferences, have you.

An electrical engineer would tell you that this is wrong. Use a 4.7K resistor
to +5.

Hi,
   Would have liked to try it but cpec does not completely build:

    "struct KProgress" undefined.

Kirti,
    Wine was written to allow MS windows programs to execute on a
    computer that runs the Linux operating system. It basically remaps
    system calls. But it is quite a lot of code. It is not perfect, but it appears
    to allow FlashMagic to run on linux.  You just type "wine FlashMagic.exe"
    The one issue I have is that when I try to display flash memory, the
    pop-up window does not display the memory contents. It just stays
    blank. So I felt the need to write my own GUI based program to talk
    to the Philips microcontrollers using Linux.  It does everything I need.
    I was able to customize so features that I found lacking in FlashMagic,
    no offense to our FlashMagic guys out there.
    I suggest that you obtain Wine and build/install it before writing your
    own program.

Ron

I notice that the ISP commands for reading data are a little buggy.
1 K reads are ok, but the data sheets say "starting address" and
"ending address". ISP read commands that span like a 8K read do
not return all the flash data. I also noticed that the maximum size
read that is returned is 4096 bytes, which includes all the '=' & address
characters like:

0000=........

Did the flashmagic design decision for 1K reads occur because of these
limitations?

My app can post windows for all the flash blocks so I can see everything
at one time. I can also view the hex file too.

You can obtain wine from gnu.org and build/install on your linux platform.

or you can write an application that talks through one of the COM ports
to send and receive data using the isp interface built into the 89c51rd2.