UART Serialout buffer question

Yokablasta · Joined: 13 Dec 2017 Posts: 19

Hello,
I have a project here that reads in strings of serial data, then processes and transmits the strings. Each string has a status header, which tells the cpu what kind of string (how many bytes) we are transmitting. I am using the hardware uart serial output buffer. Most of these strings can be transmitted FIFO, however, there is one class of string that needs to move to the front of the buffer, as soon as the last string is finished transmitting (IE, as soon as the next byte in line is one of the status headers.) I want to insert the high priority string and immediately transmit it. I am not very familiar with how to manipulate the output buffer, or if it is even possible. Can anyone recommend an approach to this?

I was hoping to move the head and tail pointers to the left and right of the string I just placed in the buffer, then once transmitted, move the head and tail back to the original values. Does this sound like the way to do this?

(BASCOM-AVR version : 2.0.8.2 )

enniom · Joined: 20 Oct 2009 Posts: 537

Have you considered OVERLAY on the sections you want to move?

MWS · Joined: 22 Aug 2009 Posts: 2262

Yokablasta · Joined: 13 Dec 2017 Posts: 19

MWS,
This makes sense, and it answers my question about whether the contents of the output buffer can be examined. If it is the case that once something gets put in the buffer, then it stoically gets worked off, then it sounds like I need to re-examine my approach to using the output buffer. Perhaps instead of printing the data as it happens, I should create a software buffer and prioritize which strings get sent to the output buffer?