• Locked Locked
  • Replies 5 replies
  • Subscribers 119 subscribers
  • Views 2953 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

Is 'mov r1,#0xab0000' right?

Gaofeng He
Note: This was originally posted on 23rd June 2011 at http://forums.arm.com

I am a beginner in ARM assembly. Recently I meet a question about that is the instruction 4'mov r1,#0xab0000' right?

As we know the MOV Instruction has an Operand2 field which contains 8bits imm8m field and a bits rotate field. But many books say that the constant can only be 0~255 means only use the imm8m filed without using the rotate field. I then download a arm instruction quick reference card PDF. It says Operand2 can represent a 32bits constant which can get by 8bits immdiate filed and the rotate. So I think Mov r1,#0xab0000 is valid. Actually I can successfully compiled the instruction in Keil uvision.

Is it true that for all ARM compilers, the instruction above will be passed with a constant value which exceed 255 but can get by 8bits immdiate and an rotate? In another word, can these instructions directly be supported by general ARM assembly compilers? For example mov r1,#0xab00.

Thanks
Parents Reply Children
No data