Hallo Harnam,

read and write signals from mcu are active low. So, correct naming is RD# and WR#, where '#' marks active low functionality.

You control 74374 by a NOR gate, but I think OR gate will be correctly? You must trigger '374 with the rising edge of WR#. 0 to 1 transition of WR# in combination with 0 from '138 gives 0 to 1 transition at CLK pin of '374 only, if WR# and select signal are OR gated.

Bye,
Kai