| ??? 05/08/08 11:06 Read: times |
#154569 - wrong shift register used ... Responding to: ???'s previous message |
Maybe I#ve found the problem. Two ICs which originally shoudl be 74HC4094 are HCF4094. I didn't know that there is a difference because I never used shift registers before. But as I looked into datasheets I noticed that the chip I use is nearly 8 times slower than the on which has to be used. Maybe this causes the problems?
On the other hand, the slower chip can be driven with 2 MHz at 5V VCC. Ist that really not enough for this application? Here are the Datasheets: 74HC4094 (ST): http://www.datasheetcatalog.org/datasheet...711_DS.pdf HCF4094 (ST): http://www.datasheetcatalog.org/datasheet...249pky.pdf Timings are on page 5 and 6 respectively. |
| Topic | Author | Date |
| software problems with DL2TM programmer | 01/01/70 00:00 | |
| that\'s the crux | 01/01/70 00:00 | |
| reading works barely - writing not a bit | 01/01/70 00:00 | |
| one of the gotchas of the LPT-port gadgets is... | 01/01/70 00:00 | |
| a few successful transactions | 01/01/70 00:00 | |
| wrong shift register used ... | 01/01/70 00:00 | |
you have no idea | 01/01/70 00:00 | |
| get DOS | 01/01/70 00:00 | |
| making progress with IC-prog | 01/01/70 00:00 | |
| no improvement - cable is ok | 01/01/70 00:00 |