hi i am final year student of electrical engineering and doing a project on 8051 microcontroller. in this project,i have to interface the 8051 to maltab for real world data.i successfully complete the interfacing and communicate serially on proteus.data which is transfer from 8051 to matlab is not accurate when i send more than one character.in single character, matlab does not show any data.plz help me,how to solve that problem as i am using 8051 first time.
When all you have is DC, a trace on the PCB can be seen as a resistor with a very low resistance.
When your current consumption is pulsed, which it is in a clocked digital circuit, then the PCB wires are no longer just resistors. They behave as if they have capacitance and inductance. So you need to take care - for example reduce the current pulsing in the wires by having decoupling capacitors as close at is possible to VCC and GND of all your chips.
If you have digital inputs unconnected, the radio-frequency energy radiated from other signals can be enough to get an open digital input to jump randomly between zero and one.