Electronic – What are the implications of a ROMLESS device

armnxpprogramming

I was looking through the microcontrollers area of Digikey and I noticed a device that i'm interested in although there is the description of "ROMLESS" in the program memory type.
http://www.digikey.com/product-search/en/integrated-circuits-ics/embedded-microcontrollers/2556109?k=LPC4330

What I take away from that is that there is no flash memory internal to the chip but since it is Read-Only memory, I question that. Maybe this mean that it needs an external EEPROM to boot the program from?

So I'm not entirely sure so here I am asking:

1) What does this exactly mean

and

2) How would this change a design?

Best Answer

Actually, it's a bit of a misnomer; there is some on-chip ROM containing boot code and a small one-time-programmable (OTP) ROM for the application to use (serial numbers, configuration data, encryption keys, etc.)

But there's no on-chip nonvolatile memory for application code (it seems they wanted to use the chip area to support more SRAM instead), which means that you need to supply some other external memory (flash, SD, hard drive, etc.) to hold the application code and data. If the external device supports random addressing, you can execute code directly from it; otherwise, you can copy code into the on-chip SRAM and execute it from there.