On Jul 14, 11:14 pm, Tom Anderson wrote:
In a ROM. To my mind, it has to be modifiable to be firmware, which makes
code in a ROM not firmware. Although thinking about it, my mind is
probably wrong on this point.

Firmware is any built in software that controls the low level
functionality of a piece of hardware. Doesn't matter how its stored.

Or it could be done with an ASIC that isn't a microprocessor. It doesn't
need to be any more than a memory controller with an encryption processor
glued on the side.

So what do you think will be running the encryption processor? I don't
know what a circuit hardwired to do something like 3DES or Blowfish or
whatever encryption Oyster uses would look like, but I suspect it
would be a nightmare to design and debug if it were even possible.

They're called "smart" because they have a microprocessor running
software that decodes commands and reads, encrypts and transmits the
requested data.

Microprocessor or ASIC?

Most ASICs these days have embedded CPUs.

B2003