| ??? 10/25/07 03:41 Read: times |
#146165 - yes, at osc/12 it's 1 MHz ... but ... Responding to: ???'s previous message |
Since Mike is probably still planning to use his i80C51, he mustn't forget that the MCU cycles external memory and MMIO with a pretty short cycle. He needs to know what the cycle length is. He also needs to note that the nRD and nWR cycles, which comprise his 'E' strobe, together with the address decoder output, are not as long as he might think, based on the cycle rate. IIRC, it's typically 3 clock ticks, nominally 250 ns at Fosc=12 MHz, per the Intel datasheet. Other MCU's may vary, of course.
RE |
| 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 |