Hi, I'm wondering if it is possible to check if a 68hc711 has the security feature enabled (by putting it into a development board) without clearing the content of the EEPROM? http://groups.yahoo.com/group/m68HC11/message/857 -- -Torgeir |
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68hc711e9 security feature
Started by ●April 29, 2004
Reply by ●April 30, 20042004-04-30
The secure devices are marked differently (they usually have an S or SEC somewhere in their name). If you have a proprietary marking on the chip that you know is a 68HC711 but don't know whether it's the secure or the regular version, don't try finding out because, in case of the secure version, placing the chip in non-user (boot) mode will lose the EEPROM contents making it useless for the original application. You can still reprogram the EEPROM with new data and re-enable security. ----- Original Message ----- From: "Torgeir Veimo" <> To: < > Hi, > > I'm wondering if it is possible to check if a 68hc711 has the security > feature enabled (by putting it into a development board) without > clearing the content of the EEPROM? > http://groups.yahoo.com/group/m68HC11/message/857 > -Torgeir |
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Reply by ●April 30, 20042004-04-30
The HC11 Reference Manual provides a method for checking security without disabling it (and, therefore, clearing EEPROM). Here's the relevant excerpt from the Manual. "The presence of the security option can be detected while the MCU is in reset by forcing the mode A (MODA) and mode B (MODB) pins to 1 and monitoring the strobe A/address strobe (STRA/AS) pin. When MODA and MODB are 1s, the normal expanded mode is requested. If security is engaged, the STRA/AS pin will act as a high-impedance input because the security option causes the MODA pin to be interpreted as a 0 even if it is a 1. In single-chip modes, the STRA/AS pin is configured for the strobe A input function. If the security mode is not engaged, the STRA/AS pin will act as the address strobe output, which can easily be recognized on an oscilloscope. This checking procedure allows the security mode to be detected without disengaging it. If the MODB pin were low in this experiment, the bootstrap mode would be requested rather than the normal single-chip mode. In the case of MODB low, care is required not to release reset because doing so would cause the security option to be disengaged." You'll most likely need to prepare a custom circuit to try this. ----- Original Message ----- From: "Torgeir Veimo" <> To: <> Sent: Thursday, April 29, 2004 10:34 PM Subject: [m68HC11] 68hc711e9 security feature > Hi, > > I'm wondering if it is possible to check if a 68hc711 has the security > feature enabled (by putting it into a development board) without > clearing the content of the EEPROM? > http://groups.yahoo.com/group/m68HC11/message/857 > > -- > -Torgeir > > > Yahoo! Groups Links |
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Reply by ●April 30, 20042004-04-30
On Fri, 2004-04-30 at 11:32 +0300, Tony Papadimitriou wrote: > The secure devices are marked differently (they usually have an S or SEC > somewhere in their name). > > If you have a proprietary marking on the chip that you know is a 68HC711 but > don't know whether it's the secure or the regular version, don't try finding out > because, in case of the secure version, placing the chip in non-user (boot) mode > will lose the EEPROM contents making it useless for the original application. > You can still reprogram the EEPROM with new data and re-enable security. Thank you for the reply. If its not a secure device, I assume putting it into non-user mode will not change it's EEPROM content? -- Torgeir Veimo < |
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Reply by ●April 30, 20042004-04-30
--- In , Torgeir Veimo <torgeir@p...> wrote: > Thank you for the reply. If its not a secure device, I assume > putting it into non-user mode will not change it's EEPROM content? If, as Tony noted, the device does NOT have a 'S' or 'SEC' in its part number, the device in question will IGNORE the setting of the NOSEC bit in the config register. You will be able to read out the ROM contents, as well as EEPROM contents, IF you can get the device into a suitable platform that will let you utilize the 'bootstrap' mode. If you do not have such a board handy, the HC11 reference manual provides a schematic for a 'minimal' HC11 setup that you could build that would allow you to get the device into 'bootstrap' mode and (with suitable tools, such as JBug11) read out the device contents. If the device in question is a 'S' or 'SEC' type device, attempting to place the device in one of the test modes will, at a minimum, erase the EEPROM contents, which will likely make the firmware on the device non-functional. On some (typically newer) HC11 secured devices, the device will prohibit entry into the test modes altogether (at least from the user's perspective) in addition to erasing the EEPROM contents. |
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Reply by ●April 30, 20042004-04-30
On Fri, 2004-04-30 at 20:20 +0000, Mark Schultz wrote: > --- In , Torgeir Veimo <torgeir@p...> wrote: > > > Thank you for the reply. If its not a secure device, I assume > > putting it into non-user mode will not change it's EEPROM content? > > If, as Tony noted, the device does NOT have a 'S' or 'SEC' in its > part number, the device in question will IGNORE the setting of the > NOSEC bit in the config register. It's labeled mc68hc711e9cfn2 from my earlier notes. Some more letters seems to be 5C47M SS019947. I can verify one more time to be shure though.. -- Torgeir Veimo < |
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Reply by ●April 30, 20042004-04-30
On Fri, 2004-04-30 at 22:29 +0100, Torgeir Veimo wrote: > On Fri, 2004-04-30 at 20:20 +0000, Mark Schultz wrote: > > --- In , Torgeir Veimo <torgeir@p...> wrote: > > > > > Thank you for the reply. If its not a secure device, I assume > > > putting it into non-user mode will not change it's EEPROM > content? > > > > If, as Tony noted, the device does NOT have a 'S' or 'SEC' in its > > part number, the device in question will IGNORE the setting of the > > NOSEC bit in the config register. > > It's labeled mc68hc711e9cfn2 from my earlier notes. Some more letters > seems to be 5C47M SS019947. I would assume it would be an MC68HC711E9CFS2 if it had the security feature.. -- Torgeir |
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Reply by ●April 30, 20042004-04-30
A "CFS" chip is a windowed, ceramic part and will usually have a
XC prefix. Bob --- Avoid computer viruses, Practice safe hex --- -- Specializing in small, cost effective embedded control systems -- http://www.smithmachineworks.com/embedprod.html Robert L. (Bob) Smith Smith Machine Works, Inc. 9900 Lumlay Road Richmond, VA 23236 804/745-2608 ----- Original Message ----- From: "Torgeir Veimo" <> To: <> Sent: Friday, April 30, 2004 5:44 PM Subject: Re: [m68HC11] Re: 68hc711e9 security feature > On Fri, 2004-04-30 at 22:29 +0100, Torgeir Veimo wrote: > > On Fri, 2004-04-30 at 20:20 +0000, Mark Schultz wrote: > > > --- In , Torgeir Veimo <torgeir@p...> wrote: > > > > > > > Thank you for the reply. If its not a secure device, I assume > > > > putting it into non-user mode will not change it's EEPROM > > content? > > > > > > If, as Tony noted, the device does NOT have a 'S' or 'SEC' in its > > > part number, the device in question will IGNORE the setting of the > > > NOSEC bit in the config register. > > > > It's labeled mc68hc711e9cfn2 from my earlier notes. Some more letters > > seems to be 5C47M SS019947. > > I would assume it would be an MC68HC711E9CFS2 if it had the security > feature.. > > -- > Torgeir > > -- ------ > Yahoo! Groups Links > > a.. To |
Reply by ●April 30, 20042004-04-30
I have some secure HC11's, I believe they are marked: 68S711E9CFN2 Even though other flavors of HC11 have a "NOSEC" bit, unless it is an "S" part, it cannot be secured. > On Fri, 2004-04-30 at 22:29 +0100, Torgeir Veimo wrote: > I would assume it would be an MC68HC711E9CFS2 if it had the > security feature.. Regards, Darrell Norquay Datalog Technology Inc. Calgary, Alberta, Canada Voice: (403) 243-2220 Fax: (403) 243-2872 Email: Web: www.datalog.ab.ca |
Reply by ●May 4, 20042004-05-04
On Fri, 2004-04-30 at 22:29 +0100, Torgeir Veimo wrote: > On Fri, 2004-04-30 at 20:20 +0000, Mark Schultz wrote: > > --- In , Torgeir Veimo <torgeir@p...> wrote: > > > > > Thank you for the reply. If its not a secure device, I assume > > > putting it into non-user mode will not change it's EEPROM > content? > > > > If, as Tony noted, the device does NOT have a 'S' or 'SEC' in its > > part number, the device in question will IGNORE the setting of the > > NOSEC bit in the config register. > > It's labeled mc68hc711e9cfn2 from my earlier notes. Some more letters > seems to be 5C47M SS019947. > > I can verify one more time to be shure though.. The labels are MC68HC711E9CFN2 5C47M SSDJ9947. Can the SSDJ indicate a secured device? Nothing matches that string on google. The 5C47M indicates the mask of the chip? What exactly does the mask number imply? I will check again with a custom circuit and a scope as suggested previously in the next weeks before I plunge into interfacing the microcontroller. -- Torgeir Veimo < |