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I want to know if there is any way to read Eeprom from an 68HC05 with an Arduino. I've been reading other SPI and I2C EEPROM's. Thanks for your help and have a nice night.

Sorry for my bad English if I write something bad but I'm still learning the language.

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  • \$\begingroup\$ Do you mean the EEPROM within the HC05 itself? \$\endgroup\$ – Ignacio Vazquez-Abrams Nov 29 '13 at 4:35
  • \$\begingroup\$ Maybe there is a way by emulating the microcontroller programmer with the Arduino. Usually in the datasheet, you can find information for programming/reading EEPROM from the chip. \$\endgroup\$ – Chirry Nov 29 '13 at 5:33
  • \$\begingroup\$ Actually with an Arduino with Optiboot bootloader Ignacio... Chirry, thanks, I'll do that this weekend... \$\endgroup\$ – Poperto Arcadio Buendía Nov 30 '13 at 19:13
  • \$\begingroup\$ How does that in any way answer my question? \$\endgroup\$ – Ignacio Vazquez-Abrams Dec 3 '13 at 2:27
  • \$\begingroup\$ I'm sorry... actually I want to read the HC05 EEPROM with the Arduino Ignacio Vazquez-Abrams \$\endgroup\$ – Poperto Arcadio Buendía Dec 18 '13 at 18:09
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First do you know if it has been secured ?? If so then its hopeless.

Its been 20 years since I last used HC05. Where from my paper copy of the data sheet. It looks like you can likely use its Standalone Bootstrap mode by appling VPP followed by setting PD5 and PD2 low, along with PD3 and PD4 to high. Then release RESET# and the HC05's bootstrap with start dumping the PROM contents at 4800 baud 8N1 out the SCI(UART) assuming a 2 MgHz crystal, starting with $0020 through $1FFF. You could just convert this to RS232 and send to a PC's Serial Port. No need for an Arduino.

This is all assuming the PROM has not been secured.

Here is an article of someone doing just this for a 7085U. My above datasheet is for the 705C8.

Note, Near the end of the 705's popularity a variety of different models came out, like the "J" and "K" which had cheaper programers. So there may likely be differences. Find the datasheets. There likely is a Standalone Bootstrap for your version that can be triggered to dump out either the SCI(UART) or SPI.

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  • \$\begingroup\$ I think he was asking about reading the EEPROM not EPROM. I mean the former can't be locked, right? I did find the datasheet but it doesn't mention having SCI or any other kind of serial communication at all and has only general I/O pins (besides VCC, VDD, XTAL etc.) So how to communicate with the chip? By making a routine for that or is there another way? \$\endgroup\$ – Luka Jan 25 at 21:37

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