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Most of this code has originated from requests and challenges on the PICList mailing list.
I tried to debug the routines as much as possible (for a hobby), but no guarantees. In case you find a bug, please let me know.
Please send any questions or comments to golovchenko@mail.ru, or the PICList, as many nice folks hang around there and most probably will be glad to help you.
| Routine Name | Size, instructions | Max timing, cycles | Temporary registers | Notes |
| Multiplication | ||||
| 24 by 24 bits | 29 | 513 | 1 | |
| Division | ||||
| 8 by 8 bits to 24 bit floating point | 41 | 413 | 1 | |
| 16 by 8 bits with Q16.16 fixed point result | 39 | 460 | 1 | |
| 24 by 16 bits (and 24 by 15) | 27/28 | 584/581 | 3 | |
| 32 by 16 bits using 16 by 16 bits with a 16 bit result | 36 | 345 | 2/4 | |
| 48 by 24 bits (and 48 by 23) | 58/51 | 1458/1266 | 5/4 | my versions at the bottom |
| Scaled 8 bit: x 256*x/y | 28 | 281 | 3 | |
| Approximate 8 bit reciprocal: 32768/x | 19 | 47 | 0 | |
| Divide 14 bit integer using a fixed point divisor and result (7Q8 format) | 27 | 264 | 0 | |
| Square | ||||
| 10 bits | 68 | 70 | 0 | this is a debugged John Payson's version |
| Routine Name | Size, instructions | Max timing, cycles | Temporary registers | Notes |
| Square Root | ||||
| 24 bit floating point | 85 | 406 | 6 | IEEE<>Microchip format conversion |
| 12 bit integer | 32 | 118 | 3 | |
| 8 bit | 20 | 66 | 2 | |
| 8 bit fast | 53 | 19 | 0 | |
| 8 bit small | 9 | 87 | 0 | Idea from Scott Dattalo, tweak by Dmitry Kiryashov |
| Powers and logarithms | ||||
| Fixed point Q0.16 log2x | 105 | 323 | 3 | also notes on xy |
| Fixed point Q6.10 2x | 121 | 291 | 4 | |
| CORDIC | ||||
| Vector magnitude, 16 bits | 147 | ~1600/800 | 4 | |
| Routine Name | Size, instructions | Max timing, cycles | Temporary registers | Notes |
| Radix Conversion | ||||
| 16 bit binary to 5 digit decimal | 68 | 226 | 0 | strips a digit at a time |
| 16 bit binary to 3 digit decimal | 34 | 108 | 0 | based on John Payson's 5 digit version |
| 16 bit binary to 3 digit decimal | 56 | 57 | 0 | based on Scott Dattalo's 8 bit BIN2BCD |
| 5 digit decimal to 16 bit binary | 35 | 36 | 0 | |
| 5 digit decimal (BCD) to 16 bit binary | 23 | 341 | 1 | |
| Miscellaneous | ||||
| 8 bit random number generator | 10 | 10 | 0 | my version at the bottom |
| Delay exactly N cycles | - | - | 0 | scalable for any N size |
| Routine Name | Size, instructions | Max timing, cycles | Temporary registers | Notes |