| ??? 03/01/06 16:29 Read: times |
#110985 - Philips 89C51Rx status byte |
I am just trying to make sure I have got my head around the status byte in the Philips 89C51Rx series of microcontrollers. My understanding is as follows:
1. At reset, if the status byte is non zero, the boot vector is used and if this is set to FC then the ISP code is called. 2. At reset, if PSEN is low and EA, P2.7 and ALE are high, this is identical to a non zero status byte and the boot vector is used again. 3. At reset, if the status byte is zero, code execution at 0000H begins (user code). So, assuming I can meet the conditions of 2), is there any reason why I should ever program the status byte to anything other than zero? Ian |
| Topic | Author | Date |
| Philips 89C51Rx status byte | 01/01/70 00:00 | |
| for factory programming? | 01/01/70 00:00 | |
| Factory programming | 01/01/70 00:00 | |
and used by NoTouch | 01/01/70 00:00 | |
| 89C51Rx vs 89V51Rx | 01/01/70 00:00 | |
| Forced Migration | 01/01/70 00:00 | |
| IAP entering on P89V51RD2 | 01/01/70 00:00 |