| ??? 02/15/05 15:26 Read: times |
#87536 - connect Responding to: ???'s previous message |
as I have said: connect the pin to Vcc.
From T89C51RD2 datasheet: Pin /EA External Access Enable: /EA must be externally held low to enable the device to fetch code from external program memory locations 0000H to FFFFH. So, as you may understand, it must be tied with Vcc to execute program from internal flash. Regards, Oleg |
| 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 |