Timeline for LDR, LDRD and STR instructions with immediate offset in ARM Cortex-M3
Current License: CC BY-SA 4.0
14 events
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| Feb 18, 2021 at 16:20 | comment | added | jwh20 | Try it yourself using the link I posted in the answer. But your question makes no sense as you are showing two different values for R5 at the same time. | |
| Feb 18, 2021 at 14:29 | comment | added | user276722 |
@jwh20 Suppose that in the instruction LDRNE R2, [R5, #960]!, R5=0x10000000, *(unsigned int)R5=0x12345678, then after the instruction is executed will R2=0x12345678 or whatever value that equals to *(unsigned int)(R5+960)?
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| Feb 18, 2021 at 3:05 | comment | added | jwh20 | BTW there are many ARM programming resources available. | |
| Feb 18, 2021 at 2:49 | comment | added | user276722 | @jwh20 Got it. Thanks for answering my question. | |
| Feb 18, 2021 at 2:47 | comment | added | jwh20 | No, MOV R4, R3 moves the value in R3 to R4. It's purely a register-to-register transfer. STRH R3, [R4] on the other hand stores the low-halfword value in R3 into the MEMORY ADDRESS pointed to by R4. So it's a register-to-memory operation. | |
| Feb 18, 2021 at 2:15 | comment | added | user276722 |
@jwh20 Thank you for your useful answer. I would like to ask whether STRH R3,[R4] is equivalent to MOV R4, R3. STRH R3, [R4] stores the value of register R3 into the address specified by R4, which is the same as copying the value of R3 into R4. Is that correct?
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| Feb 18, 2021 at 2:10 | vote | accept | CommunityBot | ||
| Feb 16, 2021 at 11:35 | comment | added | jwh20 | @YuanLinTech please return to this question and either accept the posted answer or add some comments as to why it's not helpful. | |
| Feb 14, 2021 at 19:29 | comment | added | old_timer | I think they have one called a programmers guide, something with the word programmer in the name, avoid that one. | |
| Feb 14, 2021 at 19:28 | comment | added | old_timer | 8 and 9 words not bytes, a typo | |
| Feb 14, 2021 at 19:28 | comment | added | old_timer | focus on the architectural reference manual for these details, it is all described there. The TRMs are good, arms other documents I have found lacking or confusing and in this case has typos | |
| Feb 14, 2021 at 13:12 | answer | added | jwh20 | timeline score: 1 | |
| Feb 14, 2021 at 8:33 | review | First posts | |||
| Feb 14, 2021 at 18:54 | |||||
| Feb 14, 2021 at 8:31 | history | asked | user276722 | CC BY-SA 4.0 |