| ??? 10/26/07 17:39 Read: times |
#146264 - I think! Responding to: ???'s previous message |
Russell Bull said:
Mike, you always seem to choose the most complex and torturous route to a solution.
At least I think about the potential CONS of each solution out there. I'm looking at minimizing the cons. LCDs are slow - both with the interface and the rate at with the LCD crystals will change. Also, you've got a human on the other end reading it - they are slow (compared to the processor). Yes, I know. If you're worried about the LCD tying up precious cpu time, then you're not thinking the problem through. As for using completion interrupts from the lcd - I'd say it would take a little bit of extra logic to implement this, but why? I want to cut down on my code for the LCD. One solution I choose for not waiting for the LCD was to use a 1mS tick. Each mS I would write a character to the LCD. I wouldn't have to wait, since 1mS is more than enough for the LCD controller to do its stuff. The simplest way for me to do that is to use a very low crystal speed, but then my whole processor will slow down. I don't want that. The second way I could do it is to store the data in an 8-bit latch (74HCx73) and then after 1mS, retrieve the data, but the problem is that I will have to wait 1mS to send new data, or I could overwrite existing data. Maybe I should just tie R/W of the LCD to low and make an external circuit that can process the LCD information properly, so that I don't have to use excessive waits in my code. So for a 16*2 display, a full update would take 32mS -or about 31 updates per second. I'm using a graphics display based on a KS0108 controller. |
| Topic | Author | Date |
| I\'m debating this 8052 circuit... | 01/01/70 00:00 | |
| Do you understand why that was done? | 01/01/70 00:00 | |
| I understand, but my debate is not solved. | 01/01/70 00:00 | |
| Avoid the situation! | 01/01/70 00:00 | |
| It should be ... | 01/01/70 00:00 | |
| ... | 01/01/70 00:00 | |
| startup.a51 will do just that unless modified | 01/01/70 00:00 | |
| What's a "startup.a51" | 01/01/70 00:00 | |
| C startup | 01/01/70 00:00 | |
| and if I use my own code... | 01/01/70 00:00 | |
| If you're smart enough to do that ... | 01/01/70 00:00 | |
| MMIO | 01/01/70 00:00 | |
| yes, at osc/12 it's 1 MHz ... but ... | 01/01/70 00:00 | |
| ... | 01/01/70 00:00 | |
| that's crazy | 01/01/70 00:00 | |
| Why worry? | 01/01/70 00:00 | |
| polls? | 01/01/70 00:00 | |
| If you want it to be high-speed, you won't use LCD | 01/01/70 00:00 | |
| experiment with the obvious | 01/01/70 00:00 | |
| Complexity | 01/01/70 00:00 | |
| I think! | 01/01/70 00:00 | |
| If only that were true ... | 01/01/70 00:00 | |
| Think? | 01/01/70 00:00 | |
| ok | 01/01/70 00:00 | |
| Not a matter of guessing.. | 01/01/70 00:00 | |
careful now! | 01/01/70 00:00 | |
| ASM | 01/01/70 00:00 |