vik1501
New Member
Can somebody solve this problem.
I am using 8255 in mode 0 ( all outputs latched) and connected bi-directional buffer 74LS245 at the output port A of 8255.
74LS245 is enabled by connecting pin 19 to ground. Also I set pin 1 at grd so that it is in B to A direction. Plz note 8255 port is connected to 'B' of LS245.
When I try to latch data #0ffh using uP to port A of 8255 , an unusual thins happens. The output pins of port A show voltage level @ 1.25V at all the pins. However when I remove 74LS245 and again start the program, the voltage level is @ 4.00V.
Is this a compatibility problem. How so I solve this ? :?:
I am using 8255 in mode 0 ( all outputs latched) and connected bi-directional buffer 74LS245 at the output port A of 8255.
74LS245 is enabled by connecting pin 19 to ground. Also I set pin 1 at grd so that it is in B to A direction. Plz note 8255 port is connected to 'B' of LS245.
When I try to latch data #0ffh using uP to port A of 8255 , an unusual thins happens. The output pins of port A show voltage level @ 1.25V at all the pins. However when I remove 74LS245 and again start the program, the voltage level is @ 4.00V.
Is this a compatibility problem. How so I solve this ? :?:
