| ??? 01/13/09 20:17 Read: times |
#161500 - To Hans Responding to: ???'s previous message |
Hans Van Pelt said:
while in the main loop you wait (beugh!) for TI to come on (actually you have that line commented out) and then you transmit a byte. I tried moving that line to the ISR, and I tried uncommenting the line in the main loop. It doesn't make a difference. Hans Van Pelt said:
Proper interrupt driven serial transmission would look more like this:
Trans:
CLR TI ; clear transmission flag for next trans
clr a
movc a,@a+dptr ; get character
jz exitISR ; stop if char = null
mov SBUF,A ;
inc dptr ; point to next char
What happens when I want to send just one byte? What happens when the byte does not come from code memory? Hans Van Pelt said:
Also, you have a massive flow problem! Your code goes: - reset, - init, - call send message, (stack contains return address) - (send message executes and returns), (stack is empty now) - return. The final return will return to a garbage address, as the stack will be empty at that point. You need a proper termination. My "favourite time waster" does that, at reduced energy consumption too. This is just a test file to insure that I am not losing my mind! How is the stack empty when it returns? I don't understand. 1. After initialization, there is a call to the test routine. 2. In that routine there is another call to the OutStr routine and once finished it will return to the previous routine (test) which also includes a return instruction. 3. It then returns to the "jmp $" instruction which is an endless loop. Maybe I am missing something here? I realize that this is a foolish statement, but it worked in the simulator! |
| Topic | Author | Date |
| serial interrupt? | 01/01/70 00:00 | |
| Your Problem | 01/01/70 00:00 | |
| still not working | 01/01/70 00:00 | |
| you need to flag somehow the end of transmission | 01/01/70 00:00 | |
| reply to Jan | 01/01/70 00:00 | |
| Several | 01/01/70 00:00 | |
| To Hans | 01/01/70 00:00 | |
| And my reply to Charles | 01/01/70 00:00 | |
| no interrupts works | 01/01/70 00:00 | |
| the solution | 01/01/70 00:00 | |
| Isn't that what Hans said? | 01/01/70 00:00 | |
| Perfectly????? Prolly should look again. | 01/01/70 00:00 | |
| Got to look ahead... | 01/01/70 00:00 | |
| Another thing to consider | 01/01/70 00:00 | |
| reply to Andy Neil | 01/01/70 00:00 | |
| reply to Michael Karas | 01/01/70 00:00 | |
| why is this a bad idea | 01/01/70 00:00 | |
| Exactly why not perfect !!! | 01/01/70 00:00 | |
| response to Jan Waclawek | 01/01/70 00:00 | |
| interrupts forever | 01/01/70 00:00 | |
| nope | 01/01/70 00:00 | |
Re: Erik | 01/01/70 00:00 | |
| if you HAVE to mix ... | 01/01/70 00:00 |