In an 8085 microprocessor based system the active low chip select signal of the 2K*8 RAM is connected to the address line A15. The RAM address lines are connected to A10 - A0. What is the highest address which accesses a location in the RAM?

Concept:

The size of the RAM is 2K × 8, meaning it has 2K = 2048 locations. This requires 11 address lines (since 2¹¹ = 2048), which are connected to A₁₀ to A₀.

The chip select is active-low and connected to address line A₁₅. For the RAM to be selected, A₁₅ must be 0.

Calculation:

Total address lines in 8085 = 16 (A₁₅ to A₀)

Since only A₁₀ to A₀ go to RAM, and A₁₅ must be 0 (for active-low chip select), the remaining upper address bits A₁₄ to A₁₁ can be any combination (i.e., 0000 to 1111).

To get the highest possible address within RAM: set A₁₅ = 0 (active), A₁₄ to A₁₁ = 1111, and A₁₀ to A₀ = 11111111111

\( \text{Address} = 0\text{FFF} + 7FF = 7FFF_H \)

Final Answer:

Option 2) 7FFFH