| ??? 08/18/05 08:43 Read: times |
#99633 - sorry, my mistake Responding to: ???'s previous message |
hi,
Jan Waclawek said:
What's wrong with an external memory always selected, if it is the only memory present in the system?
Nothing if there are no special requirements (for example, FRAM requires deselect IC before each access to pre-charge itself) and if you do not need with RAM power save and if neither /RD (here: /RD or /PSEN) nor /WR come low when it is not needed. Oleg Sergeev said:
Now the question for Jan: do we assume that RAM select time via /CS is fast enough in your puzzle? Jan Waclawek said:
As /CS does not change (A15 is always 1), it does not matter. Sorry, here is my mistake. I calculated timings for /RD and /PSEN which are connected to /OE of RAM but asked about /CS. So my question is not about RAM select time via /CS but about timings of RAM output data ready via /OE instead. Are they enough fast to operate at 50ns or so? Regards, Oleg |
| Topic | Author | Date |
| week puzzle III | 01/01/70 00:00 | |
| Not getting into details... | 01/01/70 00:00 | |
| you do | 01/01/70 00:00 | |
| see this | 01/01/70 00:00 | |
| Well. . . | 01/01/70 00:00 | |
| let me try | 01/01/70 00:00 | |
| eh? | 01/01/70 00:00 | |
| I`m confused with A15 | 01/01/70 00:00 | |
| Whooops | 01/01/70 00:00 | |
| and I thought that was "the puzzle" | 01/01/70 00:00 | |
| sorry | 01/01/70 00:00 | |
| and I thought that was "the puzzle" | 01/01/70 00:00 | |
| another trouble | 01/01/70 00:00 | |
| And what's wrong with /CS? | 01/01/70 00:00 | |
| sorry, my mistake | 01/01/70 00:00 | |
| what does not happend? | 01/01/70 00:00 | |
| And...? | 01/01/70 00:00 | |
| explain | 01/01/70 00:00 | |
| And...? | 01/01/70 00:00 | |
| Answer for puzzle | 01/01/70 00:00 | |
| I doubt? | 01/01/70 00:00 | |
| I doubt | 01/01/70 00:00 | |
| I agree here | 01/01/70 00:00 | |
| I wonder | 01/01/70 00:00 | |
| autodetect | 01/01/70 00:00 | |
| /PSEN | 01/01/70 00:00 | |
| there is also flaw in the reasoning | 01/01/70 00:00 | |
| Lost inverter | 01/01/70 00:00 | |
| errta | 01/01/70 00:00 | |
| Questions | 01/01/70 00:00 | |
| answers to questions | 01/01/70 00:00 | |
| Timings | 01/01/70 00:00 | |
| Ex[plain A bit more please | 01/01/70 00:00 | |
| intel app note says | 01/01/70 00:00 | |
| I do | 01/01/70 00:00 | |
| re:EA | 01/01/70 00:00 | |
| yes no doubt about it | 01/01/70 00:00 | |
| reset device | 01/01/70 00:00 | |
| three legged | 01/01/70 00:00 | |
The solution | 01/01/70 00:00 |