How to read the information in the 16KROM of the MC68HC11G5FN microcontroller - Page 1
Forum section: electronics / projects

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2023, 04:35:12 am
content: Hallo every one.I plan to rebuild a host whose main MCU is MC68HC11G5FN,The RAM chip is LH5164A,27C1001 is an external storage ROM chip.Query the MC68HC11G5FN chip information and find that it has 16K ROM storage space,I don't know if there is any necessary important information in the 16K ROM,I am copying a brand new MC68HC11G5FN. Do I also need to copy the data in 16KROM for the final success.If you know if I need to copy and how to copy, please let me knowthanks

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 07, 2023, 08:52:52 am
content: I can't helpmuch.Maybe:https://shrubbery.net/~heas/willem/kmitl/C11evb.htmhttp://www.hc11.demon.nl/thrsim11/68hc11/literatu2.htmhttp://www.radioscanner.ru/files/electronics/file3742/

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2023, 09:16:44 am
content: Thanks.It seems that a 16K ROM is related to MODA and MODB.I don't know if I need to write a boot in the new 68HC11G5FN to use it, or if I need to use the new 68HC11G5FN directly。Because both the MODA and MODB jumpers on my motherboard are suspended

author: Benta
author_rank: Super Contributor
timestamp: September 07, 2023, 08:13:59 pm
content: Quote from: daisizhou on September 07, 2023, 09:16:44 amYou can't write anything, as it's a mask ROM. The question is, whether you need the contents at all.A "standard" mask programmed MC68HC11G5 would have a customized part number, something like SC123456FN or ZC123456FN.That's not the case here. It's stamped with MC68HC11G5FN1 which is unknown for customized devices.The clue is in the FN1suffix.The1signifies that Motorola/Freescale manufactured it to contain the "BUFFALO" monitor in the ROM. Now, whether you need this is an open question, completely up to you.

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 07, 2023, 08:25:10 pm
content: The schematics show pullups in MODA/B pins.If the jumpers are not populated, then the CPU boots with both at "1" level.

author: Benta
author_rank: Super Contributor
timestamp: September 07, 2023, 09:48:51 pm
content: Quote from: DavidAlfa on September 07, 2023, 08:25:10 pmInteresting. That means the MCU boots in Expanded Mode (=from external EPROM), which means the internal ROM plays no role at all.Probably the MC68HC11G5FN1is the only one available as off-the-shelf part.

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2023, 10:56:20 pm
content: Thank you for your reply.You mean that I only buy an identical MC68HC11G5FN1,Then copy the firmware in 27C1001 (eeprom) and PLD (22V10),And then fully connect the circuit, i can copy the circuit board, right？In other words, as long as I purchase the same model MC68HC11G5FN1, the software part is not related to it，Because the software part is in the EEPROM or PLD chip

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 07, 2023, 10:58:54 pm
content: Theorically, yes.I don't know if there's some sort of copy protection, like using the unique ID from the CPU (No idea if the HC11 has that) or other methods.So you're planning to copy the entire design? Is that what we're helping for?

author: Benta
author_rank: Super Contributor
timestamp: September 07, 2023, 11:16:30 pm
content: Quote from: DavidAlfa on September 07, 2023, 10:58:54 pmCould be. But more likely a desperate repair effort. MC68HC11G5FN1 are on the "unobtainium" list today, and they were mainly produced for the eval-boards. Never a real off-the-shelf volume part.

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2023, 11:18:29 pm
content: Yes, The original factory has stopped production of the entire machine.I hope to regain it, so I can only make it myself in my spare time, and I know it's difficult,I am purchasing every chip like it and assembling it

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2023, 11:20:43 pm
content: I have purchased one in the second-hand market and I am currently unsure if it will work properly

author: Benta
author_rank: Super Contributor
timestamp: September 08, 2023, 12:54:05 am
content: Well, good luck.As said, you only need to clone the EPROM and the PAL.

author: daisizhou
author_rank: Super Contributor
timestamp: September 08, 2023, 01:17:39 am
content: Ok, thank you for your help

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 08, 2023, 07:13:53 am
content: To my understanding, you could use any MC68HC11G5, not requiring exactly the MC68HC11G5FN1.Whether it has internal rom or not, it won't be used with MODA/MODB=1, so any variant should work,right?Coincidently, I have like 50x 68HC11A1FN and 20x 68HC11E1CFNE2 I got from my job, they were throwing them away.But it's the 52 pin version, the MC68HC11G5 is 84 pin.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 08, 2023, 08:09:32 am
content: Quote from: daisizhou on September 07, 2023, 10:56:20 pmBear in mind the 22V10 may be protected.

author: daisizhou
author_rank: Super Contributor
timestamp: September 08, 2023, 08:27:13 am
content: Understood. Currently, in order to maintain consistency, I have chosen MC68HC11G5FN1. If I succeed or reverse the source code, I will consider using another model instead of MC68HC11G5FN1

author: daisizhou
author_rank: Super Contributor
timestamp: September 08, 2023, 08:35:08 am
content: This is the internal firmware and logic diagram of 22V10,And the definition diagram.If you could understand and analyze it, it would be perfect.Thanks

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 08, 2023, 08:52:23 am
content: You already have the schematic, the eeprom contents, that's all you need to replicate it.

author: daisizhou
author_rank: Super Contributor
timestamp: September 08, 2023, 09:10:04 am
content: No, in the actual circuit, the RAM chip uses a 28 pin LH5164.That is to say, uPA13 and uPA14 are no longer connected to the RAM chip, because the LH5164 channel only has A0-A12.So I cannot be 100% sure that the connection lines of 22v10, LH5164, and 27c1001 are consistent with the schematic diagram of the old versionThis is the ultimate goal of helping analyze firmware-->https://www.eevblog.com/forum/microcontrollers/help-who-can-reverse-compile-27c1001-firmware-internally-i-encountered-difficu/?topicseen

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 08, 2023, 09:28:38 am
content: Well, that's not the way anyways.You must physically take the board and measure the connections, it would take only few hours.While analyzing the fw will take a lot more.That's more like paid job, don't expect anyone spending days working in it for free.If It uses a smaller RAM, it could be that it simply didn't need so much memory, the rest of the design wouldn't require any changes, the program would be made to not access more than 8KB RAM.