3 ms·

Fun fact - the MSP430 ISA is based on the PDP-11 ISA.

• pryelluw 10y ago
  Do you have a source I could read? This is super interesting.
  • bryanlarsen 10y ago
    So was the Motorola 6800. I think it would be more surprising if they did everything from scratch rather than modelling it on some pre-existing work... https://en.wikipedia.org/wiki/Motorola_6800 https://en.wikipedia.org/wiki/Motorola_6800
  • deleted 10y ago
    [deleted]
  • samlittlewood 10y ago
    Best independent source I can find is http://www.cpushack.com/CPU/cpu4.html#Sec4Part14 http://www.cpushack.com/CPU/cpu4.html#Sec4Part14. I noticed whilst writing a verilog implementation - seeing the @PC+ relative modes for immediate data made me dig out my PDP-11 reference card. The number of addressing modes has been halved, gaining a bit for register encoding, and the status register is now in the register file (R2), and R3 is used to generate various constants depending on mode. Compare and contrast: * https://en.wikipedia.org/wiki/PDP-11_architecture#CPU_registers https://en.wikipedia.org/wiki/PDP-11_architecture#CPU_regist... * https://en.wikipedia.org/wiki/TI_MSP430#MSP430_CPU https://en.wikipedia.org/wiki/TI_MSP430#MSP430_CPU
    • pryelluw 10y ago
      Awesome, thanks.