Is a multiplexer needed to read from memory

Question

we need to enable a register to write into that register, which is done using a decoder.
even if we enable 1 register using decoder, given that RD(bar) is 0, all registers can still produce an output. And if all registers can respond, output would get corrupted.
so would we not need to select the output of that register , maybe by multiplexing?  
is multiplexing used between output buffer and memory in this figure ? is it something else? i am not able to find on the net

Dave Tweed · Answer

There is implicit multiplexing, created by providing each register with a 3-state output driver, and enabling only one driver at a time onto the bus. That's why you see the $overline{text{RD}}$ and $overline{text{CS}}$ lines connected to the Output Buffers in your diagram. The buffers are only enabled when $overline{text{RD}}$ and $overline{text{CS}}$ are both low at the same time.

Answered by Dave Tweed on November 23, 2021

Is a multiplexer needed to read from memory

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