A memory map is how the processor sees the world. When you design a system with a microcontroller, it uses address lines to control where it reads data from. Some of these addresses are internal to the chip, others go to the outside world.

There are a bunch of chips connected to the processor (peripherals) that can do all kinds of different things. Some are memories, some convert an analog voltage like a MAP sensor into a digital value that the processor can use.

= P4 Memory Map =

There is an excellent general summary of the P4 memory map on Ludis' site.

-- AlexHarford - 30 Jun 2006

I believe that the addresses in the $3nnn range are shared addresses in the 16045148 chip and are not actually in the microcontroller.

-- CliffHarris - 5-31-2011