| ??? 12/09/05 21:58 Modified: 12/09/05 21:59 Read: times |
#105013 - Looks ok Responding to: ???'s previous message |
Erik Malund said:
If this schematic is accurate, you are trying to read the switches backward through a '373 that's impossible. He is trying to read his switches through a '244 tri-state buffer, which, at least as far as the bus interface goes, appears to be done correctly. I don't see a '373 being used for switch input anywhere. If this schematic is NOT accurate, why you trying to make it more difficult for us to help?
based on your mnemonics (which can be read as I do or any other way) you assume what ALE latches into the 373 is data, it is not, it is "low address" WHY do you make things so difficult for yourself with external memory??? Erik This appears to be class lab work for a first course in microcontrollers. Working with devices on the microprocessor bus is an important skill, regardless of whether it is an actual memory or some memory-mapped I/O device. The use of multiple devices on the bus in the same application is also essential, as address decoding is a necessary skill. --Sasha Jevtic |
| Topic | Author | Date |
| 8052 with a decoder - help! | 01/01/70 00:00 | |
| in addition .. | 01/01/70 00:00 | |
| can not work ! | 01/01/70 00:00 | |
| Program store? | 01/01/70 00:00 | |
| 8052 with a decoder - not a -31 | 01/01/70 00:00 | |
| im sorry :( | 01/01/70 00:00 | |
| if the problem you refer to is no code m | 01/01/70 00:00 | |
| ok | 01/01/70 00:00 | |
| The ground pin | 01/01/70 00:00 | |
| Yes, there are problems | 01/01/70 00:00 | |
| grounded | 01/01/70 00:00 | |
| picture | 01/01/70 00:00 | |
| No picture | 01/01/70 00:00 | |
| thoguht so .. | 01/01/70 00:00 | |
| Tristate latch output enable | 01/01/70 00:00 | |
| YOU ARE GOD! | 01/01/70 00:00 | |
| i am curious .. | 01/01/70 00:00 | |
| Welcome to embedded systems | 01/01/70 00:00 | |
| Thanks A Lot | 01/01/70 00:00 | |
| WHAT memory??? | 01/01/70 00:00 | |
| RAM | 01/01/70 00:00 | |
| it is .. | 01/01/70 00:00 | |
| another pic | 01/01/70 00:00 | |
| Another bad picture | 01/01/70 00:00 | |
| updated schematic | 01/01/70 00:00 | |
| AIM | 01/01/70 00:00 | |
| Look at U8 | 01/01/70 00:00 | |
| thank you | 01/01/70 00:00 | |
| KISS | 01/01/70 00:00 | |
| New problems ... | 01/01/70 00:00 | |
| picture | 01/01/70 00:00 | |
| Switches | 01/01/70 00:00 | |
| here you go sasha | 01/01/70 00:00 | |
| sry here .. | 01/01/70 00:00 | |
| Not clear | 01/01/70 00:00 | |
| if this is accurate, you are trying to r | 01/01/70 00:00 | |
| Looks ok | 01/01/70 00:00 | |
| the '244 output is connected NOT to a | 01/01/70 00:00 | |
| But wait, there's more | 01/01/70 00:00 | |
| So, how are they connected? | 01/01/70 00:00 | |
| New Questions | 01/01/70 00:00 | |
| 5.7V | 01/01/70 00:00 | |
| I have no recollection of asking about a | 01/01/70 00:00 | |
| Pull ups are definitely a good idea | 01/01/70 00:00 | |
| Look For... | 01/01/70 00:00 | |
| here .. | 01/01/70 00:00 | |
Ratings | 01/01/70 00:00 |