What is difference between MSP430 and MSP430X?

开发者_StackOverflow社区Any comparison table available?

The basic change for the 430X architecture was to introduce a 20 bit address range to allow addressing outside the 64K available on the original 430 devices. There are a new set of instructions that operate on the 20 bit address in parallel with the old style 16 bit instructions. e.g.

CALL  ; takes a 16 bit address    
CALLA ; takes a 20 bit address

PUSH  ; Push the bottom 16 bits of a register onto the stack
PUSHA ; Push the full 20 bit register

The existing code compiled for a 430 based processor will run within the bottom 64K address space of the 430X processor. In the development tools (IAR and probably Rowley) you can specify a memory model so that the longer function calls and other 430X specific instructions are not generated if you ensure that your code does not cross the 64K boundary.

Wikipedia's usually good for this sort of thing. It looks like it's to increase the address space to 1MB on the X from 64K on the regular.

http://en.wikipedia.org/wiki/MSP430#MSP430X_20-bit_extension

The MSP430X extension has only 20 bit address space. So the CALLA takes only a 20 bit address.