Programming HC05

[alexspin]

Hi all,

I'm new of this forum!!

I have experiences about freescale and motorola MCUs but now I'm interfacing to a (for me....) big problem.

A customer asked me to extract program from a programmed MC68HC705B16N and write it into a new one.

This customer has developed that application but for an HW failure of our server have lost all, the source and the compiled file to write, so that is very important for they.

Thanks for your help!!!

BR

[bigmac]

Hello, and welcome to the forum.

Provided the security bit is clear, you should be able to read the contents of PROM using the programmer.  However, if the security bit has been programmed, you will not be able to access the code.

Regards,

Mac

[alexspin]

Hi, thanks for the welcome.

The security bit is bit 0 of the EEPROM oprion register ( OPTR ) at location 0x0100. Is it correct (page F-9 datasheet MC68HC05B6 rev. 4.1)?

For the programmer, they have realized a programmer board with the schematics shown on the datasheet (page F-17) with serial interfce.

As I tell before they have lost all of their data, the programming software also.

Is it possible to know wich protocol used in this serial interface?

Thanks!

Alex

[alexspin]

Hi,
we have done some steps in order to program this device. We have understand that with serial bootstrap we need to send the opcode to execute reading. It's ok?
We try to send it but the chip not respond.

The configuration of the PDs is this:
PD1 = GND
PD2 = GND
PD3 = VDD
PD4 = VDD

After reset the two leds stay on, I don't think is a good thingh.

Any ideas?
Thanks.

BR

[bigmac]

Hello,

Using the rudimentary parallel bootstrap circuit, you will not be able to read the MCU PROM contents.

You would probably need to use an evaluation board, or other suitable programmer, to be able to read the PROM contents for this obsolete device.  I am not familiar with the details of the read algorithm.

Regards,

Mac