Timeline for Efficient size of FIFO buffer for UART
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
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| May 20, 2018 at 10:12 | comment | added | Masood Salik | Point 7 is valid but it's not quantified. My devices are programmed to send data in every 15ms and the controller receive it transmit the new control parameters to these devices. I think that since my arrival rate and service rate is same; i should not be needing the buffer. But it didn't work. I have to use the buffer size approximately 1.5x of the data bytes. Why this contradiction? And every UART channel has its owns circular queues. | |
| May 20, 2018 at 8:02 | comment | added | jonk | Many times, on projects I've worked on, we started out with the MORE EXPENSIVE device that had the maximum RAM. Then, later, after we knew for sure our RAM requirements, we'd select a cheaper part. | |
| May 20, 2018 at 6:29 | comment | added | Michael Karas | But @jonk, if the OP and his colleagues test and validate the product and its software up toward production with larger than needed circular buffers in place it is reasonable to guess that the extra consumed RAM was not detrimental to the product operation. The testing that should be going on is to validate whether the buffers are large enough with a comfortable margin to cover worst case corner conditions. That would result in making the buffers bigger if there were negative findings. | |
| May 20, 2018 at 5:20 | comment | added | jonk | You covered my thoughts pretty well (I wouldn't have written #8, since I think that one is too obvious.) But I think a simple answer to the OP can be found in #7. Simply make the buffers too large and track a "high water" mark during operation. After enough testing, a solid idea of how to size the buffers will emerge and can be used to establish them in the final version. | |
| May 20, 2018 at 3:12 | history | edited | Michael Karas | CC BY-SA 4.0 |
added 7 characters in body
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| May 20, 2018 at 2:57 | history | answered | Michael Karas | CC BY-SA 4.0 |