| ??? 02/01/07 13:00 Read: times |
#131874 - YES, those two pins are Responding to: ???'s previous message |
So 80C592 needs external pullup resistors for P1.6 and P1.7.. Does that mean that port 1 is incompatible with the original 8051 port?
YES, those two pins are, AND, as should be, it is clearly indicated in the datasheet. I guess we all have been caught by "using experience" (my foray into the SILabs deviates as an example) and the unfortunate fact is that nobody has yet (to my knowledge) published a datasheet with a specific chapter named "variances". To maintain 'compatibility' re external memory interface, the only port available for new drivers is P1. So when a peripheral is added (I know of the 66x and IIC - same story) the "added feature pin(s)" must be on P1. Then when the added feature require OC/OD you find "nonstandard" P1 pins. Erik |
| Topic | Author | Date |
| 80C592 port 1 problem | 01/01/70 00:00 | |
| I tend to remember, YOU look it up in the datashee | 01/01/70 00:00 | |
| waiting for a techie, I checked | 01/01/70 00:00 | |
| so a pullup is necessary? | 01/01/70 00:00 | |
| 80c592 port 1 | 01/01/70 00:00 | |
| YES, those two pins are | 01/01/70 00:00 | |
80C592 port 1 problem (solved) | 01/01/70 00:00 |