| ??? 10/10/08 08:28 Read: times |
#158953 - more options... Responding to: ???'s previous message |
Andy Neil said:
1. Extend the SFR address space
2. Map things into XDATA instead 3. Map things into DATA or IDATA instead 4. Use a prefixed instruction (prefix = 0A5h) to access extra SFRs, maybe even as "shadows" of direct/indirect RAM. IIRC, the Philips' MX does (not only) this. 5. Use indirect addressing via dedicated SFRs. At the expense of 3 "classical" SFRs (as address low - address high - data) you have a space for 65536 extra SFRs with no collision with the existing ones. The placement of SFRs into XDATA space is not unseen - in fact, it happens very often in SoC-like chips. JW |
| Topic | Author | Date |
| SFR Paging - advantages ? | 01/01/70 00:00 | |
| how else would you do it | 01/01/70 00:00 | |
| RE: how else would you do it | 01/01/70 00:00 | |
| more options... | 01/01/70 00:00 | |
RE: more options | 01/01/70 00:00 | |
| So smart? | 01/01/70 00:00 | |
| Not very encouraging....:-( | 01/01/70 00:00 | |
| Located this document.. | 01/01/70 00:00 | |
| a way to handle it | 01/01/70 00:00 | |
| Getting clear on this paging stuff | 01/01/70 00:00 | |
| No new concept! | 01/01/70 00:00 | |
| maybe, maybe not | 01/01/70 00:00 |