| ??? 12/07/05 10:36 Read: times |
#104803 - A nice self-made tool ! Responding to: ???'s previous message |
It is of course not a real emulator, but a tiny tool which can help a lot, especially when connected to a good oscilloscope !
First, the controller must have the program (at least the critical part) externally placed, and so addressed by P0-P2. You can take 2 times 8 bit comparators 74HC688, and connect one set of their inputs to the address bus and the other (to define the address) to 16x DIPSWITCH. PSEN from the processor comes to Enable input of the comparator, and Output of the first to Enable of the next. You can then set the desired address on the DIPSW (you get it in the LST file) and start the program. When it reaches the address, you get Low on the output, which you can use to trigger the scope (or toggle the FF in a simpler case, or to stop the program, or something else). By that you also verify that the program was there. Material: 2 x 74HC688, DIPSW, 74HC74+LED (good to have), and (???). Some much more advanced could then start tracing (!), ie. saving next addresses, using PSEN signal, but that of course requires much, much more of hardware, work and experience. Regards, Slobodan |
| Topic | Author | Date |
| how to debug without an ICE? | 01/01/70 00:00 | |
| possible, sure, as easy no | 01/01/70 00:00 | |
| printouts-simulator-monitor-quasiICE-ICE | 01/01/70 00:00 | |
Roll your own? | 01/01/70 00:00 | |
| 01/01/70 00:00 | ||
| That's what I do | 01/01/70 00:00 | |
| Me too | 01/01/70 00:00 | |
| not pantyhose | 01/01/70 00:00 | |
| microscope and nuts | 01/01/70 00:00 | |
| other tools | 01/01/70 00:00 | |
| A nice self-made tool ! | 01/01/70 00:00 | |
| This, of course blows any modern design | 01/01/70 00:00 | |
| What are we talking about ? | 01/01/70 00:00 | |
| It DOES have to do with what you suggest | 01/01/70 00:00 | |
| another low-cost tool | 01/01/70 00:00 | |
| The LED | 01/01/70 00:00 | |
| digital line with OSCOPE | 01/01/70 00:00 | |
| seems print is a very good choice for me | 01/01/70 00:00 | |
| Make your own | 01/01/70 00:00 |