| ??? 02/16/05 10:08 Read: times |
#87634 - 1st things 1st please Responding to: ???'s previous message |
To rule out any of the possible problems described here tie EA, PSEN and ALE to Vcc through a pullup. This is how i always use my RD2 and never had problems like this (had many others though). Timing can be an issue but we have to know what crystal you are using. Anyway to see it flashing it has to be be low freq. i recon. BTW, 1k series resistor for TTL gives more then enough light on most common LED's. |
| Topic | Author | Date |
| Problem getting 8051 chip to work | 01/01/70 00:00 | |
| tie ~EA pin to Vcc | 01/01/70 00:00 | |
| tie Vpp/~EA pin to Vcc | 01/01/70 00:00 | |
| to connect or not? | 01/01/70 00:00 | |
| conbnect | 01/01/70 00:00 | |
| If it helps.... | 01/01/70 00:00 | |
| Reset Capacitor | 01/01/70 00:00 | |
| connect | 01/01/70 00:00 | |
| T89C51RD2 | 01/01/70 00:00 | |
| This device is ISP | 01/01/70 00:00 | |
| VCC and GND? | 01/01/70 00:00 | |
| I think you do not load | 01/01/70 00:00 | |
| Series resistor for LED? | 01/01/70 00:00 | |
| 74F14 | 01/01/70 00:00 | |
| give me +1 too | 01/01/70 00:00 | |
| done | 01/01/70 00:00 | |
| Sorry | 01/01/70 00:00 | |
| LED Polarity | 01/01/70 00:00 | |
| Does not seem to be the cause | 01/01/70 00:00 | |
| Ouch! | 01/01/70 00:00 | |
| FAST-TTL and breadboarded design | 01/01/70 00:00 | |
| Ground bounce | 01/01/70 00:00 | |
| Bad news 74F =( | 01/01/70 00:00 | |
| HCT? | 01/01/70 00:00 | |
| LS, HCT and maybe AHCT | 01/01/70 00:00 | |
| Got it | 01/01/70 00:00 | |
| wire wrap and breadboards | 01/01/70 00:00 | |
| I use protoboard | 01/01/70 00:00 | |
| the problem with that is | 01/01/70 00:00 | |
| Thanks | 01/01/70 00:00 | |
| Why do you want to use 74F chips? | 01/01/70 00:00 | |
well... | 01/01/70 00:00 | |
| maybe you are still in ISP mode? | 01/01/70 00:00 | |
| 1st things 1st please | 01/01/70 00:00 | |
| Thanks | 01/01/70 00:00 | |
| bounce on non PCB | 01/01/70 00:00 | |
| Analytical thinking | 01/01/70 00:00 |