Rationale behind the Modebits



hi
The mode bits of ARM7 in CPSR are of 5 bit width when the processor is
capable of operating in one of the 7 modes.
I would like to know what is the rationale behind using 2 additional
bits instead of going only for 3 bits(that can represent max of 8
states).
Has it got to do with anything related to simpler implementation logic
or is it for any particular historic reasons associated with ARM
processor

kishore

.



Relevant Pages

  • Rationale behind the Mode bits
    ... The mode bits of ARM7 in CPSR are of 5 bit width when the processor is ... capable of operating in one of the 7 modes. ...
    (comp.sys.arm)
  • Re: Rationale behind the Mode bits
    ... capable of operating in one of the 7 modes. ... ARM is more than ARM7. ... You have to consider the people struggling with architecture-specific code, device upgrades, etc. ...
    (comp.sys.arm)