| ??? 08/03/05 12:14 Read: times Msg Score: +1 +1 Informative |
#98743 - documentation Responding to: ???'s previous message |
"the bible" chapter 3
http://www.semiconductors.philips.com/acrobat/v...WARE_1.pdf page 24 figure 31 show that when !WR is emitted P2 hold the high address and P0 hold the data. Thus, if you have only one 16 bit external register and do not need to read and no external memory (code or data you can write 16 bits in one go by movx if your 16 bit external register is connected to P2P0. mov dph high bits mov a low bits movx @dptr,a OR mov P2, high bits mov a, low bits movx @ri,a I would recommend that whenever 16 bit atomic access to an external register is required to use e.g. an ARM or an XA, if you still want to use the '51 the inteface to an atomic 16 bit register can fairly easily be implementd in a (C)PLD or FPGA. Erik |
| Topic | Author | Date |
| Changing address to data ?, Opinion. | 01/01/70 00:00 | |
| Not Possible Kurnia ! | 01/01/70 00:00 | |
| explanation | 01/01/70 00:00 | |
| Good Answer,not Good Question | 01/01/70 00:00 | |
| Ask Erik? | 01/01/70 00:00 | |
| Ask Erik? | 01/01/70 00:00 | |
| possible | 01/01/70 00:00 | |
| Possible | 01/01/70 00:00 | |
| re:possible | 01/01/70 00:00 | |
| Students | 01/01/70 00:00 | |
| Speed | 01/01/70 00:00 | |
| Found it! | 01/01/70 00:00 | |
| documentation | 01/01/70 00:00 | |
| Yes, its a good idea ! | 01/01/70 00:00 | |
| If you do it that way | 01/01/70 00:00 | |
| speed? really? | 01/01/70 00:00 | |
| the source of this discussion was a post | 01/01/70 00:00 | |
| addressed 16-bit movx write | 01/01/70 00:00 | |
Thank's for the opinion | 01/01/70 00:00 |