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Make a program to set the pin0 on port D to high, and afterward to low. For measuring we will use an oscilloscope.

a.       We will note the levels (both voltage and current) when it is high and when it is low. According to the datasheet ( page 21 ) it states that the pin RD0 is TTL buffer. Due to that we can see on page 247 that the high output will minimum be 3.3Volts when we use I_OL = 8.5mA and V_DD = 4.5V. For the low output the voltage would be a maximum of 0.6 when we use I_OH = -3mA and V_DD = 4.5V.

b.      The total current specification states that there can at maximum run 200 mA on portD and portC combined

c.       No more than ±20 mA can run through a single pin