wejos Member May 19, 2010 #1 i read 12c508a is otp so i just wanted to be sure. i was looking at some code online and noticed when the author assigned the pins it's reversed (compared to 16f84) Code: MOVLW b'00000000' MOVWF GPIO if i wanted GP0 act as input should it be b'00000001' or b'10000000'? thanks guys, joey --------edit cannot add to subject Last edited: May 19, 2010
i read 12c508a is otp so i just wanted to be sure. i was looking at some code online and noticed when the author assigned the pins it's reversed (compared to 16f84) Code: MOVLW b'00000000' MOVWF GPIO if i wanted GP0 act as input should it be b'00000001' or b'10000000'? thanks guys, joey --------edit cannot add to subject
P Pommie Well-Known Member Most Helpful Member May 19, 2010 #2 Yes, the 12C508 is OTP. If you get the 12F508 then it is reprogrammable. For GP0 to be input it's b'00000001'. Mike. Last edited: May 19, 2010
Yes, the 12C508 is OTP. If you get the 12F508 then it is reprogrammable. For GP0 to be input it's b'00000001'. Mike.
wejos Member May 19, 2010 #3 still the same start from right. is the "for GP0 to be "*output*" just typo? many thanks Pommie.
P Pommie Well-Known Member Most Helpful Member May 19, 2010 #4 Yes, should have said input. I'll edit it. Mike.
C colin55 Well-Known Member May 19, 2010 #6 You can use the 12C508 again if you nop out the old program.
Nigel Goodwin Super Moderator Most Helpful Member May 19, 2010 #7 colin55 said: You can use the 12C508 again if you nop out the old program. Click to expand... You can't NOP out the old program, as NOP is all ones, and programming can ONLY make ones become zero, not the other way round. There are certain very limited things you can do - but it's really a waste of time - just use a 12F508 if you really want a 508.
colin55 said: You can use the 12C508 again if you nop out the old program. Click to expand... You can't NOP out the old program, as NOP is all ones, and programming can ONLY make ones become zero, not the other way round. There are certain very limited things you can do - but it's really a waste of time - just use a 12F508 if you really want a 508.
P Pommie Well-Known Member Most Helpful Member May 19, 2010 #8 colin55 said: You can use the 12C508 again if you nop out the old program. Click to expand... No you can't. Mike.
colin55 said: You can use the 12C508 again if you nop out the old program. Click to expand... No you can't. Mike.
wejos Member May 19, 2010 #9 guys quick follow up... since there's no 12c508 option in simulation software, will the 12f508 option do. i'm using real pic simulator (shareware version). i'm afraid when i programmed it to the actual PIC something might go wrong. thanks, joey
guys quick follow up... since there's no 12c508 option in simulation software, will the 12f508 option do. i'm using real pic simulator (shareware version). i'm afraid when i programmed it to the actual PIC something might go wrong. thanks, joey
C colin55 Well-Known Member May 19, 2010 #10 You can use the 12C508 again if you nop out the old program. Click to expand... You add the new program AFTER the nops. You can't NOP out the old program, as NOP is all ones, and programming can ONLY make ones become zero, not the other way round. Click to expand... This is not true. I have just NOP'd out an old program and the result is 000. And added the new program after the zero's.
You can use the 12C508 again if you nop out the old program. Click to expand... You add the new program AFTER the nops. You can't NOP out the old program, as NOP is all ones, and programming can ONLY make ones become zero, not the other way round. Click to expand... This is not true. I have just NOP'd out an old program and the result is 000. And added the new program after the zero's.
wejos Member May 19, 2010 #11 everything is honky dory in sim using 12f508 but will it really work once programmed in 12c508?
Nigel Goodwin Super Moderator Most Helpful Member May 19, 2010 #13 Strange how your memory plays tricks - I've just been and checked the datasheets, true enough, NOP is all zeros. The 12F508 and 12C508 are supposed to be pretty well interchangeable, with the 12F508 replacing it. Side By Side - Product Comparison (PIC12C508 PIC12F508) Last edited: May 19, 2010
Strange how your memory plays tricks - I've just been and checked the datasheets, true enough, NOP is all zeros. The 12F508 and 12C508 are supposed to be pretty well interchangeable, with the 12F508 replacing it. Side By Side - Product Comparison (PIC12C508 PIC12F508)
wejos Member May 19, 2010 #14 thanks for the info, mike, colins, super moderator nigel. i'll look up to this NOP part later.