Switching over to Propeller C

A project log for Arduino Graphics Card

Advanced graphics for anything from homebrew computers to weather reporting boxes and everything that can communicate over 3.3-5v UART.

Dylan BrophyDylan Brophy 09/25/2018 at 19:010 Comments

Until I move away from the propeller chip entirely for my graphics, I will want to make my code run faster.  I want more RAM free to store sprites and 3d lines, and I want better framerates.

I have always used spin for programming the Propeller chip, however I have recently discovered that Propeller C is now faster than spin.  To be exact, for some programs it can be twice or even 5x as fast!!!

I got this data from here.

I think my program could have a decent increase in speed using propeller C.  There are two caveats however:

  1. Most of the CPU time is spent in assembly routines, not spin code
  2. The communication bottleneck is (mostly) in the 115200 bps serial, not the spin code

To speed up the assembly routines I could overclock the propeller chip.  This has been done.  The propeller reaches about 100 Mhz on most chips if I remember correctly.

The communication bottleneck could be fixed by adding a SPI communication option.  I must keep serial however to keep a certain level of backwards compatibility with my older versions.