| ??? 12/22/04 15:24 Modified: 12/22/04 15:31 Read: times |
#83627 - A little O/T help with UART Crystal |
Hi,
Like the subject says, this is a touch off topic, but I'd really appreciate some help on this one. I designed a 8051 circuit using a Philips 16C550 uart, as I needed 2 uarts. I had some PCB's made, but then had some problems buying the Philips uarts, so I bought TI 16C550C's instead - assuming they were identical (yes, I know. ASSUME makes an ASS out of U and ME). The TI chips don't work, and the only difference I can see is in the clock circuitry. Diagram below shows the 2 alternative Philips clock circuits from the datasheet - I used the top one - on the left, and the TI on the right. Question is, can anyone see any way I can get it working by just changing capacitor values? or do I need to mod my PCB's (ouch)? Thanks for your time. edit>> Just realised I forgot the values for C5 and C6. C5 is 10 - 30 pF and C6 is 40 - 60 pF  |
| Topic | Author | Date |
| A little O/T help with UART Crystal | 01/01/70 00:00 | |
| Rethink | 01/01/70 00:00 | |
| Using current limiting resistor? | 01/01/70 00:00 | |
| Track cuts x200 | 01/01/70 00:00 | |
| I see no way | 01/01/70 00:00 | |
| full chip numbers | 01/01/70 00:00 | |
| Rp is missing with TI's chip! | 01/01/70 00:00 | |
| Thanks Kai | 01/01/70 00:00 | |
| Linear operation | 01/01/70 00:00 | |
| Resolution - I think..... | 01/01/70 00:00 | |
| Part Numbers | 01/01/70 00:00 | |
| the resistor | 01/01/70 00:00 | |
Both: Limiting and phase shifting | 01/01/70 00:00 | |
| Crystal oscillator reference. | 01/01/70 00:00 | |
| Thanks. | 01/01/70 00:00 |