I am using ARM Cortex R4F core and i want to know about the J bit in the CPSR/SPSR Field.
What is the purpose if this bit?
As per the Document, we can read the J bit value as 0. Is this condition is always true?
And if i want to enable this bit, How can i do that?
Can anyone please explain me this?
Seems clear enough:
It's a bit that reads as zero.
Putting "Cortex R4F J bit CPSR/SPSR" into google also gives:
Which suggest that it would only be '1' if the Jazelle instruction set were present
How to write the J bit to 1 then?
As msr cannot be used to set it as 1.
shivam30 said:How to write the J bit to 1 then?
Why would you want to do that?
As noted above, it tells you about what's built into the chip - so writing to it is meaningless!
You just can't set it. Checkout the Arm-v7-R reference manual.