| ??? 12/03/04 19:10 Read: times |
#82491 - AJMP vs SJMP Responding to: ???'s previous message |
But is there anny advantage in using sjmp?
Yes, absolutely. While there is no codesize or execution time advantage, there is nothing more pesky that an AJMP that goes beyond a page limit. If the module that the linker happen to link as the fourth has some AJMPs any change in the first 3 modules can (according to Murphy - most likey will) make some AJMP in module 4 go to the other side of a page boundary. The SJMP has a reach the AJMP has a boundary and, while linking can change the boundary, it can not change the reach. My policy: If there is more than 2k available AJMPs are outlawed. Not becuse they are per se 'bad' but because the time it takes when the linker push them across a boundary. Erik |
| Topic | Author | Date |
| sjmp vs ajmp | 01/01/70 00:00 | |
| as you said | 01/01/70 00:00 | |
| Different jmps | 01/01/70 00:00 | |
| re:AJMP, SJMP | 01/01/70 00:00 | |
| AJMP is 2 bytes LJMP is 3 | 01/01/70 00:00 | |
| LJMP was not the question | 01/01/70 00:00 | |
| AJMP vs SJMP | 01/01/70 00:00 | |
| Relocable. | 01/01/70 00:00 | |
| relocatable | 01/01/70 00:00 | |
| Re:Relocatable | 01/01/70 00:00 | |
| relocatable - not in a 51 | 01/01/70 00:00 | |
| Relocatable Code is Valid | 01/01/70 00:00 | |
| Not JMPs, relocatable | 01/01/70 00:00 | |
| I can anticipate all kinds of situations | 01/01/70 00:00 | |
| If I can devise concepts others will too | 01/01/70 00:00 | |
| "driver". | 01/01/70 00:00 | |
| Re: driver | 01/01/70 00:00 | |
maybe... maybe not. | 01/01/70 00:00 | |
| 16M derivatives... | 01/01/70 00:00 | |
| SJMP is 2 bytes | 01/01/70 00:00 | |
| Maybe he means additional bytes | 01/01/70 00:00 | |
| yes. | 01/01/70 00:00 |