| ??? 05/16/03 07:34 Read: times |
#45612 - RE: can not write to port(s) (89s8252) Responding to: ???'s previous message |
I'm at work right now, so I don't have a chance to test anything. Thanks to Dennis and Erik for there patience and understanding in these trying times.
@ Denis - I'll write an empty function call and put it in the second level of the next 'wait' loop. My code is interal not external. At first I let EA float, then when Jon ask what I did with the pin I thought I should tie it to gnd. I didn't read. but non the less I tried running the program on the chip with EA hi/float/gnd ant the result was always the same. I did do some addtional testing and found that if I set P3=0x00. The port is infact set to 0x00 and if I set the P3=0xff the port is infact set to 0xff. So I tend to believe what you described in your last message to me is my problem. @ Erik - the only thing I am doing with the chip is trying to turn a led off and on. I'm not using the serail port. I am aware that each pin of port 3 will blink at different freqs. I hook the pin of P3 which I wish to monitor to the input of a 74ls14 to avoid any current issues. I do use a 4.7k pull up resistor. And I can verify that the code I wrote to the chip is infact on the chip. I don't think i ever programmed the chip with EA being tied to gnd. I let it float(not good i know). I will try both of your suggestions later tonight, and post my results. Eric |



