| ??? 01/22/08 21:11 Read: times |
#149866 - So ... what does "generally" mean to you? Responding to: ???'s previous message |
Andy Neil said:
Andy Neil said:
Generally speaking, a display is an output device - so you wouldn't necessarily expect to be able to read-back anything that you'd sent to it?
Of course, the RAM itself can be read and written - it could just be that no interface is provided for the host to read-back what it wrote...? Richard Erlacher said:
Apparently you need to have another look at the datasheet, Andy. And what datasheet, exactly, would that be? I didn't mention any specific device - I said, "generally speaking...". Also, the OP hasn't stated what specific device - or even controller. See also: http://www.8052.com/forum/read.phtml?id=149844 now you refer to Andy Neil said: Ap Charles said:
I mean which display has only "Write-Only Memory" Please provide the LCD display part number{/quote] I don't know if there are any specific parts - my point was just that it would not be unreasonable to suggest that a display (any sort of display - LCD module or otherwise) is essentially an output device and, therefore, it would not necessarily provide access to read-back what had been written to it. It would appear that you're going on about something that you don't even know exists. Yes, CRT's generally are output-only. The interface to them, as seen from the computer, is not, however. If you really believe that "generally " requires that at least one such instance exists, perhaps you could come up with one? I will, of course, grant you that there are plenty of those little half-dollar PIC circuits that turn a conventional character LCD into a write-only device, for want of pins, and lots of hobby projects don't use the write enable because they're afraid of it, but I'm sure you appreciate that that sort of device isn't what the O/P is going to have to use. If he wants to read something, he clearly can't use a write-only medium. RE |
