Subroutine storing
Anyone has any insight into how pic deals with storage of registers when entering a subroutine? There doesn't seem to be a designated stack pointer. Maybe use indirect addressing, and use the SFR as a stack pointer? Things would really get ugly when you have nested subroutines if we don't have a stack
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Permalink Reply by Kenny Kim on
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actually, there probably is a stack, where the pic puts the return address when a subroutine is called, just no idea where it is
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Storage of registers inst a problem. Theres only really one register (which is the working register) everything else is RAM/data memory. There probably is a stack for return addresses. No idea where that's located though
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My TA said it can deal with like 10 nested subroutines before u need to do anything manually regarding the return address. But i think if u need to save and restore a register you just use a temp variable
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yea so I've ask this question below, how do we make a temp. variable that can store things?
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test 0x70 udata_shr
test res 1
and then when I want to store something in W into test:
movewf test
is this correct?
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I don't know what test 0x70 does, I think udata_shr automatically puts the register at the shared address located at the bottom of every bank. but yeah, movwf moves w into test
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