• Locked Locked
  • Replies 5 replies
  • Subscribers 119 subscribers
  • Views 3856 views
  • Users 0 members are here
2025 survey

We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.

Options
Related
How was your experience today?
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Bit-band data size clarification

Wei Zhang
Parents
  • Note: This was originally posted on 17th August 2011 at http://forums.arm.com


    The one-bit per word mapping and data representation is fixed, however, the instruction dictates what size AHB transactions are used to perform the bit-band access.

    If the peripheral being accessed via the bit-band alias has different behaviour or limitations depending on whether it is accessed via an 8, 16 or 32-bit transaction, then LDRB/H can be used to select what size transaction is performed.

    hth
    s.


    Thanks for clarification!

    Could you give one example where a peripheral being accessed via  bit-banding alias has different behavior or limitations depending on  whether 8, 16 or 32 access?

    Thanks.
    Zhang Wei
Reply
  • Note: This was originally posted on 17th August 2011 at http://forums.arm.com


    The one-bit per word mapping and data representation is fixed, however, the instruction dictates what size AHB transactions are used to perform the bit-band access.

    If the peripheral being accessed via the bit-band alias has different behaviour or limitations depending on whether it is accessed via an 8, 16 or 32-bit transaction, then LDRB/H can be used to select what size transaction is performed.

    hth
    s.


    Thanks for clarification!

    Could you give one example where a peripheral being accessed via  bit-banding alias has different behavior or limitations depending on  whether 8, 16 or 32 access?

    Thanks.
    Zhang Wei
Children
No data