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ATMega1284P ELPM instruction issue
??? ATMega1284P has 128k flash so addr is > 16 bit, hence the RAMPZ and ELPM usage rather than LPM ...     In Flash you normally have code! on a AVR the code is 16...
Sunday, 31 March 2019 - 14:03
ATMega1284P ELPM instruction issue
You write : The load from 0x0859 loaded the correct value, the others did not. How do you know that ? and how do you know to start at 0x0859 ?   Remember that flash is 16...
Sunday, 31 March 2019 - 13:32
SREG C Bit on MUL (unsigned) instruction
If you want to learn more about the different MUL instruction then read the old Atmel AVR201 appnote, hos microchip it's  AN_1631 : Using the 8-bit AVR Hardware Multiplier
Sunday, 31 March 2019 - 08:54
How Reliable Are MCU's?
I remember back in 1980 a friend had a 6502 that didn't work in a UK 101, but fine in a PET2001.  After a lot of tests it was just one instruction where a flag in some...
Saturday, 30 March 2019 - 17:56
#define of a pin does not always work?????
I don't don't know the answer, but first thing I would look at is the ASM output, it should give a hint to where the problem is.     Add: And the stupid...
Friday, 29 March 2019 - 15:20
SREG C Bit on MUL (unsigned) instruction
from #3 Interesting to observe that SER (set on all reg bits) change no flags, while CLR (set off all reg bits) sets SVN=0, Z=1, there should be a strong reason for such decision...
Friday, 29 March 2019 - 11:06
Why command ADIW has only two positions of dd?
And remember that the opcode only save code space not speed.(it take 2clk)  A SUBI on low byte and then a SBCI on the high byte can do the same, and work for all 16bit values...
Wednesday, 27 March 2019 - 08:36
Question about timer0 and relative branch out of reach error
In general only use BREQ etc. for things “inside” the block you are working with. In this case invert the branch use BRNE over the a rjmp (as cliff showed). If rjmp can’t...
Tuesday, 26 March 2019 - 10:54
Antique CPUs for sale!
The 4414 was actually the first AVR I used professionally. The chip have never been made, the die is a 8515 that is told to be ½ size. And before we went to production it was...
Tuesday, 26 March 2019 - 09:37
Atmega168a RX Interrup doesnt appear to trigger
I'm not 100% sure but I belive that you will need to read UDR0 in the ISR, (can't just flop the bit for test) . But you should at least get 1 ISR   And depending on the level...
Monday, 25 March 2019 - 14:47
What is the role of delay counter that inside clock logic ?
the delay is for slow rising power, so reset don't get released to early.
Friday, 22 March 2019 - 13:33
Copying strings in ATTiny416 unexpectedly painful
Perhaps stupid but I assume you have tried to compile with –Og as optimizer level.   
Thursday, 21 March 2019 - 14:29