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RM48L952ZWT Interfacing with 1 wire EEPROM

Other Parts Discussed in Thread: HALCOGEN

Hello, We are using a RM48L952ZWT processor. To interface with a 1 wire EEPROM part, is the only choice is hardware team connects via a GPIO on this processor (and then writing our own software low level device drivers for access) -- or is there a better option, and we can use HalCoGen to tune and autogenerate any low level drivers that can be used to access this EEPROM? Thank you.

  • Unfortunately, there is no support for external peripherals at this time. i.e., if you choose to use an external EEPROM and interface via a GPIO through bit banging/custom driver, we have no way to support this. If there is still some opportunities for the interface, it might be worth while to look at the capabilities of the N2HET module(s). There are several examples in the forum posts of using the N2HET for communications such as SCI, SPI, and I2C which may be helpful in developing support for the one-wire EEPROM interface.

    Dependent on the amount of EEPROM memory and write/erase cycles needed, the Hercules devices do support emulated EEPROM memory in flash Bank7 of the devices.
  • Hi. Thank You. So it is better to use one of the NHET terminals for interfacing with the one wire EEPROM interface instead of GPIO terminal, since at least would would have some examples to go by. I was looking up the emulated EEPROM in Reference Manual around your suggestion comment "Dependent on the amount of EEPROM memory and write/erase cycles needed, the Hercules devices do support emulated EEPROM memory in flash Bank7 of the devices." So, can the hardware engineers actually physically connect a one-wire EEPROM part to flash bank 7 RM48 interface, and then via software we are accessing the EEPROM using the same flash drivers we use to access Flash (autogenerated via HalCoGen) ? Or would we still have to write our own EEPROM drivers to access the EEPROM connected to bank 7. If this is what you mean, do you have a link to a schematic or description I can send to our hardware engineers to see if they understand how to do this connection and if amount of EEPROM memory and write/erase cycles needed fall within the accepted scope?
  • Hi Tammy,

    N2HET is a very versatile module and can be programmed to support many different protocols/wave form sequences. If you do a search on SPI and/or SCI emulation with NHET, you should be able to find the posts on this topic. I am not certain of the protocol you need for your 1-wire EEPROM so I cannot assure that this would be 100% feasible. This is something you would have to evaluate. If, though, you could not implement using an N2HET program, you could then simply use the N2HET pin assigned as a GPIO to bit bang like you had planned anyway.

    In regard to EEPROM emulation, the device as 4 - 16kB sectors of flash in Bank7 intended to be used as EEPROM emulation in flash. Halcogen includes the drivers for this. The EEPROM bank is rated at up to 100K write/erase cycles. This would eliminate the need for an external EEPROM altogether provided the 100K write/erase cycles per byte and total of 64KBytes of space is acceptable.