| ??? 01/17/07 04:48 Read: times |
#130945 - ... Responding to: ???'s previous message |
Neil Kurzman said:
Did you check if the PART will work at DC, many older ones do not. Yes, and it does work with DC. 1 instuction is 12 clocks. I thought it is that. Since it takes 12 pulses on xtal1 to generate 1 instruction, wouldn't there be a point inside those 12 pulses where the data port of the microcontroller enters the high impedance state? because if there is, then I can connect a buffer between the parallel port and the shared data bus, and when the high impedance state is on, I could then allow the parallel port data to go through the buffer. I think that it takes 1 or maybe 2 clock cycles to actually load the instruction from the data bus to the internal registers of the 8051, and the rest of the cycles are for processing. for now, I will look at the 8051's data sheet, and see if it can help me further. You will have yo excuse the lack of help. The point of veiw is that you are tring to invent something very obsolete. That's ok. At least I'm trying to invent something for myself. You can buy an ISP chip for $10 from digi-key. Nah. |
