What is difference between MSP430 and MSP430X?

开发者_StackOverflow社区Any comparison table available?

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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.

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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

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