| ??? 12/09/05 00:29 Read: times |
#104936 - Tristate latch output enable Responding to: ???'s previous message |
Edgardo Gonzalez said:
i thoguth i fixed it with the tristate buffer .... but i do have the 8052's /EA tied high The problem is that the output enable is conditioned only upon the presence of /RD. The result is that whenever you try to read from any external data memory address, the buffer's outputs will be driven, causing contention with the output drivers of the RAM, should you be reading from it. You need to add logic such that the outputs of the tristate buffers are enabled only when /RD is active and the access is to the address you've assigned to your switch input latch. In other words, make /OE on your tristate buffers be a logical combination of /RD and a decoder output. --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 |