Specifications

understandable form that the user will be able to comprehend. The

microcontroller has 256 Kbytes Flash Memory which will hold our programming

and allow the program to be modified in the future should more features be

added to the system. The 30 Kbytes RAM on the chip should allow the system to

run sufficiently fast.

CPU Characteristics:

 C compiler optimized instruction set

 Modified Harvard architecture

 16-bit wide data path

 24-bit wide instructions

 Linear program memory addressing up to 4M instruction words

 Linear data memory addressing up to 64 Kbytes

 Two 40-bit accumulators

 Sixteen 16-bit General Purpose Registers

 Software Stack

 32/16 and 16/16 divide operations

 16 x 16 fractional/integer multiply operations

 256 Kbytes Flash Memory

 30 Kbytes RAM

The microcontroller has 85 I/O pins that can be programmed to work with other

devices. This number is above what is required by our design and therefore

expansion of the system is possible. System expansion is something that will

occur after the initial prototype as been developed. The I/O pins can output

between 3.0 and 3.6 V and 4 mA.

I/O Characteristics:

 85 programmable digital I/O pins

 Output pins can drive from 3.0 – 3.6V

 Wake-up/Interrupt-on-Change on up to 24 pins

 4 mA sink on all I/O pins

 All digital Input pins are 5V tolerant

The SPI protocol will be used to interface the main microcontroller with the

ZigBee wireless chip and the 802.11b wireless chip. The microcontroller only

allows for 2 modules to be connected via SPI at one time so our design cannot

include any further SPI connections.

3-wire SPI:

 2 modules supported

 8-bit and 16-bit data supported

 All serial clock formats and sampling modes supported