| ??? 11/07/08 08:11 Read: times |
#159877 - ready-made device Responding to: ???'s previous message |
Richard Erlacher said:
This is quite true, but several of the timing + RAMDAC devices I've seen have the RAMDAC addresses externally accessible, IIRC. In reality, I guess, all he has to do is to attach an 18-bit-wide RAM (or three paralleled 256 x 8 SRAMs, or the equivalent, using only 6 of the bits) to his three 6-bit color channels. Yes, he can do this, but then it's not a RAM*DAC* anymore, it's a look-up table (LUT). OK, just terminology-hair-splitting. Anyway, 16-bit RAMs are not that expensive today, so he can do the full resolution natively, no need for the lookup (it has its merits though, such as less data to be written by the microcontroller - which is usually a good thing - at the cost of certain constraints in resulting picture - but the same holds for character-based displaying schemes). Richard Erlacher said:
Actually, I believe they're rated for 2.5 MHz or greater in their later incarnations, with the 2 MHz limit mainly impacting the bus interface. I believe this is true - I don't think it's necessary to look it up exactly. The faster variety was marked usually 68B45. However, when ticked up to the limits, they run really hot. Richard Erlacher said:
A few of those EPSON devices might work, but will be difficult to implement in prototype, not that it's much easier with current-generation programmable devices. Oh yes, how true. Richard Erlacher said:
Much depends on whether he wants a working display, as he might if he's doing this on his job, or if he wants to learn how to do this sort of thing. Again, 100% true - it boils down to the resources Bert wants to throw at this issue. Richard Erlacher said:
Can you suggest a commercial device that actually does this job on its own? I know of none. I think there is none. Those who want to do it the easy way (which is already a small market, including the hobbyists) are served by the modules which do have the controller on-board. JW |
| Topic | Author | Date |
| How do you drive a RGB color LCD display? | 01/01/70 00:00 | |
| Look for processors or display controllers | 01/01/70 00:00 | |
| Search? | 01/01/70 00:00 | |
| Epson | 01/01/70 00:00 | |
| Thanks | 01/01/70 00:00 | |
| Back to basics | 01/01/70 00:00 | |
| Richard, you flooded Bert's connection... | 01/01/70 00:00 | |
| It's not as easy as one might think | 01/01/70 00:00 | |
| ready-made device | 01/01/70 00:00 | |
| buy an evaluation board | 01/01/70 00:00 | |
| a quick peek into the code library | 01/01/70 00:00 | |
That's what I would recommend | 01/01/70 00:00 |