Contents
How much ROM does a 32 bit ARM MCU have?
The 32-bit ARM SAM3X8E has 512KB ROM and 96KB of RAM onboard. This means that if I flash a binary to it that is, say, 400KB in size, and that consumes, say, 80KB RAM (max) at runtime, then that binary will “fit” on that MCU.
Is the ROM of an MCU NAND flash?
But executing directly from the nand flash, a few million read cycles might take just a second or so. If codes is directly executed from a flash chip then that chip must be a NOR flash chip. Most microcontrollers also include real ROM inside the chip, for storing bootloaders etc.
Which is faster, executing a program from ROM or ram?
For microcontroller that offer the option of executing from RAM, that is probably faster, likely being the main point of using additional RAM space to execute code from. There may also be some fetch overlap issues. In some cases it might be faster to execute from ROM because it is a separate memory and RAM access can be going on concurrently.
What kind of ROM is in a microcontroller?
Most microcontrollers also include real ROM inside the chip, for storing bootloaders etc. This ROM is often a mask ROM which is really ROM, “Read Only Memory” meaning it cannot be written to at all by the user, it’s content is fixed in the chip design using one via mask.
How much flash memory does a MCU have?
The example should include routines to erase, write and read the flash memory. Take into account that MCU internal flash has some limitations. If your MCU has 128 Kb of Flash or less, you will probably have only one block of flash (1 block with several sectors, see the Reference Manual for more details).
How big does a binary need to be to run on a MCU?
This means that if I flash a binary to it that is, say, 400KB in size, and that consumes, say, 80KB RAM (max) at runtime, then that binary will “fit” on that MCU. However, I would not be able to flash an 800KB-sized binary onto the chip, nor would I be able to run a binary that consumes 1MB RAM at runtime.
Is there a limit on how much RAM a computer can have?
And there’s more bad news: This 4GB memory limit is shared between RAM and other devices (e.g. video, audio and network memory) so this further reduces the amount of available RAM to 3 – 3.5GB in most cases.