| ??? 01/14/07 21:11 Read: times |
#130800 - Synchronisation Responding to: ???'s previous message |
Costas Mimis said:
That is one of my problems. I can't view the signals because i don't have access to a logic analyzer. How about a dual-channel scope? Even a single channel scope would help. After CS goes low (08831) D0 goes out of tri-state and transmits 8bits on 8 clock cycles. Yes, I've scanned the datasheet, but does CS go low and does D0 go out of tri-state in your circuit? Assuming that i don't have the right synchronisation, how is it possible to get constantly an FF value on SPDAT? You need to know whether or not the ADC is actually outputting something other than FF. That's where getting some visibility with a scope comes in to play. CS provides the synchronization on the '831 device, so not having the right synchronization either means no CS or the clock edges are wrong relative to CS. I can see that the ADC's 8-bit output would be shifted relative to what the SPI peripheral expects, but we'll hold off on that until you get some kind of result. Is it possible that D0 of ADC does not get out of tri-state at all? Sure, one way would be if it never got a CS. |
| Topic | Author | Date |
| microwire&ISP | 01/01/70 00:00 | |
| Do you mean SPI? | 01/01/70 00:00 | |
| Microwire, SPI, and I2C (or TWI or TWSI) | 01/01/70 00:00 | |
| i ment SPI | 01/01/70 00:00 | |
| Microwire & SPI not different? | 01/01/70 00:00 | |
| Compatibility | 01/01/70 00:00 | |
| Pin activity? | 01/01/70 00:00 | |
| Pin activity | 01/01/70 00:00 | |
| Synchronisation | 01/01/70 00:00 | |
| Tracking signals | 01/01/70 00:00 | |
| clocks and dividers | 01/01/70 00:00 | |
| Re: clocks and dividers | 01/01/70 00:00 | |
oscillator and SPI clk | 01/01/70 00:00 |