| ??? 03/13/07 04:54 Read: times |
#134827 - Epp requires a bit less logic and is WAY faster Responding to: ???'s previous message |
It's also more easily controlled, timing-wise.
EPP creates some hardware strobes for you that you'd otherwise have to generate in softwaree on the PC side. Those strobes are the rate-determining step, and, while they're on the order of 1 microsecond long in EPP, their minimum is quite a bit longer in software. EPP's been aroung for a much longer time than you may believe. I've been fiddling with it since the early '90's. The EPP hardware on the PC side allows you to write a long-word to the port, and its hardware shuffles the bytes out for you, one at a time. Of course, it's your job to demultiplex that data correctly. Input works the same way. It has a data port at base+4 and a control/status port at base+3, where base is the SPP address. The thing also provides a WAIT line, so you can synchronize what you're doing. RE |
| Topic | Author | Date |
| 8051 board somewhat working | 01/01/70 00:00 | |
| Give us a clue then.How does it partialy work?? | 01/01/70 00:00 | |
| HC AC ???? | 01/01/70 00:00 | |
| you will most likely need pullups | 01/01/70 00:00 | |
| pull ups | 01/01/70 00:00 | |
| be more specific | 01/01/70 00:00 | |
| interesting tests | 01/01/70 00:00 | |
| interesting they may be, but | 01/01/70 00:00 | |
| to verify | 01/01/70 00:00 | |
| interesting they may be, | 01/01/70 00:00 | |
| Checksum? CRC? | 01/01/70 00:00 | |
| hmm | 01/01/70 00:00 | |
| You probably need an oscilloscope | 01/01/70 00:00 | |
| sorry for asking | 01/01/70 00:00 | |
| not the first... (or last :-) | 01/01/70 00:00 | |
| Maybe my naging helped ... | 01/01/70 00:00 | |
| why EPP? | 01/01/70 00:00 | |
| why epp can be faster | 01/01/70 00:00 | |
| Epp requires a bit less logic and is WAY faster | 01/01/70 00:00 | |
| about that schematic ... | 01/01/70 00:00 | |
| a matter of taste | 01/01/70 00:00 | |
| I have to agree ... | 01/01/70 00:00 | |
you may not have discovered this | 01/01/70 00:00 | |
| you have to investigate | 01/01/70 00:00 | |
| indeed | 01/01/70 00:00 | |
| Amazed! | 01/01/70 00:00 | |
| What? | 01/01/70 00:00 |