| ??? 01/07/06 09:20 Modified: 01/07/06 10:22 Read: times |
#106770 - Difficult ! Responding to: ???'s previous message |
Jeez if I wanted to generate 999 Hz that will be 1/999 = 0.001001001001001001001001001001001 sec.
If I make my counter increment every 0.5 usec to toggle port pin after reload I will regenrate the following frequencies:
Actual Actual Period rounding Frequency Error(Hz)
--------- ------------- -------- ---------- ---------
999 0.001001001 0.001001 999.000999 0.001
998 0.001002004 0.001002 998.003992 0.004
997 0.001003009 0.001003 997.008973 0.009
996 0.001004016 0.001004 996.015936 0.016
995 0.001005025 0.001005 995.024875 0.025
994 0.001006036 0.001006 994.035785 0.036
993 0.001007049 0.001007 993.048659 0.049
992 0.001008065 0.001008 992.063492 0.063
991 0.001009082 0.001009 991.080277 0.080
990 0.001010101 0.001010 990.099009 0.099
989 0.001011122 0.001011 989.119683 0.120
. . . . .
. . . . .
551 0.001814882 0.001815 550.964187 -0.036
. . . .
331 0.003021148 0.003021 331.016219 0.016
. . . . .
7 0.142857142 0.142857 7.00000700 0.000
The problem in this case I need a 20 bit reloadable counter. Mahmood |
| Topic | Author | Date |
| frequency generation | 01/01/70 00:00 | |
| Use an NCO | 01/01/70 00:00 | |
| Microcontroller emulates NCOs | 01/01/70 00:00 | |
| Nice but... | 01/01/70 00:00 | |
| we can think of something | 01/01/70 00:00 | |
| nothing special | 01/01/70 00:00 | |
| how about a PLL (Phase Locked Loop) | 01/01/70 00:00 | |
| PLL | 01/01/70 00:00 | |
| 0 ? | 01/01/70 00:00 | |
| Part no? | 01/01/70 00:00 | |
| Clock speed | 01/01/70 00:00 | |
| 0 Hz Frequency | 01/01/70 00:00 | |
| Differenece between... | 01/01/70 00:00 | |
| If Max is 1 kHz, ... | 01/01/70 00:00 | |
| more details | 01/01/70 00:00 | |
| Difficult ! | 01/01/70 00:00 | |
| 8253? | 01/01/70 00:00 | |
| Mode 3 | 01/01/70 00:00 | |
| mode 3 again | 01/01/70 00:00 | |
| Example | 01/01/70 00:00 | |
| 1MHz / 1001 | 01/01/70 00:00 | |
| Concretely... | 01/01/70 00:00 | |
| Overview of functions | 01/01/70 00:00 | |
| What do you think? | 01/01/70 00:00 | |
| why not '52? | 01/01/70 00:00 | |
| is it possible? | 01/01/70 00:00 | |
| its an option | 01/01/70 00:00 | |
please i need to square wave osscillator | 01/01/70 00:00 |