??? 09/01/06 15:00 Read: times |
#123507 - I wouldn't say that ... Responding to: ???'s previous message |
Erik Malund said:
Richard Erlacher said:
If they're newbies, they should become acquainted with decoding memory space and attaching memory-mapped peripherals anyway. I used to have memory mapped I/O in virtually everything I made, and it served me well, but I have not used it for the last 3 years. There are so many modern ways of expanding I/O (or not even having to expand) that I question the value of 'educating a newbie' in the use of MMIO. The value of learning something that, while still used, is on the way out is questionable for those that are just starting. I do not question that familiarity with MMIO is useful, just doubt that is shoud be part of 101. Richard Erlacher said:
However, I'm of the opinion that newbies learning to program 805x series parts should use the "real McCoy" and not some distant cousin, at least while they're learning. paraphrasing: "driver education should never take place in any car built since 1960" Erik I think you're exaggerating a bit here, Erik. I didn't say that, but I did suggest that driver education should not include the operation of the in-car DVD, cellphone, or stereo system and other features not an essential part of basic operation of the automobile. They can learn that after they've learned the basics. My position on that is, in part, based on the many posts we've had over the past couple of years, clearly demonstrating that few newbies have even the faintest notion of what the logical system organization is, and why. I do fundamentally agree that it's not essential that they learn to use external peripherals first-off, but they should understand the basics, and nothing shows them that as well as seeing the code memory and the data memory on the prototype board. It's difficult enough for them to grasp the separate notion of XRAM vs IRAM and other odditites that Intel introduced with this series. Programming classes seldom touch on such matters. Once they've "hooked-up" an 8032 and compared it with, say, a 68HC11 or similar, they'll immediately have opportunity to grasp the concepts. This guarantees nothing, of course, but it gives them the chance. With the 8032, they can develop code with which to handle the serial port, the timers, the interrupts, among other internal features. Once they're there, they can, if they wish, fool around with parts that have internal code memory. I think it's still a "stretch" for students, and we seemingly encounter a lot of them here, to grasp the somewhat convoluted approach to data memory in the 805x family. The segregation of XRAM vs IRAM, etc, is a mite twisted, by basic "computer science" standards. I don't think it hurts to have "newbies" start with the elements presented in an obvious way. If they're learning to drive in the school parking lot, they don't need airbags and seatbelts. If they can't manage that with non-fatal outcome, they deserve to die. RE |