| ??? 06/19/07 08:04 Read: times |
#140993 - PROMs, EPROMs, and alternatives Responding to: ???'s previous message |
Well, PROMs are really extinct nowadays... (believe me, we are using some in our legacy products and it is really hard to get some for quite a couple of years... anybody remembering Signetics and MMI? :-) )
Although EPROMs are on the go... And, both require some quite fancy hardware to be programmed, (relatively) high voltages and such... Not typically found on common digital logic boards - these are the chips for which device programmers have been built... So, moving to more modern waters, the typical way how to accomplish this is to get a chip with EEPROM, but with appropriately modified programming hardware. These are used in payphone cards (although these are on their way to the past, too, they might still be available). Have a look at smartcards/secure memories at Atmel and Infineon, for example. An another option would be, to use a microcontroller with builtin EEPROM, and write the firmware so that from the outside view it is a one-time-programmable "token". Among '51 derivatives, some of the LPC9xx's, maybe some of the low-end SILabs(?) and perhaps the AT89S8253(?) might be suitable (but I personally would use a cheap AVR for this purpose - please don't beat me :-) )... JW |
| Topic | Author | Date |
| Write once bit by bit memory read many times | 01/01/70 00:00 | |
| i think that PROM is your solution, | 01/01/70 00:00 | |
| OTPROM? | 01/01/70 00:00 | |
| I'd rather say | 01/01/70 00:00 | |
| Not a complete solution? | 01/01/70 00:00 | |
| black box | 01/01/70 00:00 | |
| PROMs, EPROMs, and alternatives | 01/01/70 00:00 | |
| bit by bit? | 01/01/70 00:00 | |
| some PROMs were actually written bit-by-bit... | 01/01/70 00:00 | |
| what level of security? | 01/01/70 00:00 | |
| XILINX | 01/01/70 00:00 | |
| What happens when the memory gets full? | 01/01/70 00:00 | |
| full? | 01/01/70 00:00 | |
Add-only memory from Maxim/Dallas | 01/01/70 00:00 |