| ??? 01/08/06 00:08 Read: times |
#106812 - Different value in Port 0 and on Pins. |
Hi Everyone,
Can anyone tell me why and/or how one can end up with a different value presented on the pins associated with Port 0 than in the register Port 0? I am sending an 8-bit value over the serial port (UART) to an AT89C51RC2. That value is then MOV(ed) to A(ccumulator), tested and MOV(ed) to P0. The problem is that the number being received via UART is a different value than the number presenting on the pins P0.0 - P0.7. (I confirm the number received over the UART by looking at both the received and echoed characters with an oscilloscope). It turns out that even when I run the simulation (debugging) of the program in Keil µVision2 it also shows different values in the Port 0 register and on the Port 0 pins. Can someone tell me how this can be? Is there some setup bit that I overlooked? |
| Topic | Author | Date |
| Different value in Port 0 and on Pins. | 01/01/70 00:00 | |
| Register is not the port | 01/01/70 00:00 | |
| similar happened here | 01/01/70 00:00 | |
| Not pull up issue | 01/01/70 00:00 | |
| re not pull up issue | 01/01/70 00:00 | |
| And you use pull-ups at port 0? | 01/01/70 00:00 | |
| Code | 01/01/70 00:00 | |
| PRE tag !! | 01/01/70 00:00 | |
| Just experimenting with PRE | 01/01/70 00:00 | |
| one step forward, two back.... | 01/01/70 00:00 | |
| old code | 01/01/70 00:00 | |
| Sorry but | 01/01/70 00:00 | |
| The perks, and the pull ups | 01/01/70 00:00 | |
| ideal system | 01/01/70 00:00 | |
| Code | 01/01/70 00:00 | |
| Yep. That's really what I want to do | 01/01/70 00:00 | |
| Everybody Stop | 01/01/70 00:00 | |
| Problem Solved | 01/01/70 00:00 | |
| Hey Craig or Steve | 01/01/70 00:00 | |
Remember | 01/01/70 00:00 |