Re: Wich 16-bit MCU?


Robert Latest <boblatest@xxxxxxxxx> writes:
Another question, maybe really stupid: Skimming over some of these
datasheets I've noticed the absence of any externally available,
"classical" address and data bus. Everything seems to be
general-purpose I/O. Does that mean that I have to implement my own
protocol for addressing external devices on a bus, or can the I/O
pins be somehow switched into "von Neumann" mode?

As an example, the m32c chip is split into two halves with separate
Vcc for each half. One half can be GPIO or a classical CPU bus, the
other half is GPIO or peripheral I/O (A/D, serial, I2C, etc)

So you can have a 3.3v CPU side with ethernet and SRAM (or SDRAM on
the m32c/83), and a 5V side for peripherals and serial ports. Or you
can have a bazillion 5V GPIO ports. It pretty much allows you
pin-by-pin configuration of what that pin does, with some pins
handling up to ten different functions.
.

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