Blockram: RAM model read/write

Thanks everyone for the tips.

But I really will need some definitive help on this. I am trying this for a few days now, but have not achieved knowledge enough to make this work.

Here is the latest code.

	-- Write into RAM
	vram_wraddress_sig <= A - x"2000";
	vram_wren_sig <= (not Wr_n) or (not MReq_n);
	process (Clk_Z80)
	begin
	if Clk_Z80'event and Clk_Z80 ='1' then
		if Wr_n = '0' and MReq_n = '0' and A >= x"2000" then
			vram_data_sig <= DO_CPU;
		elsif Rd_n = '0' and MReq_n = '0' and A >= x"2000" then
			vram_q_sig_reg <= vram_q_sig;
		end if;
	end if;
	end process;		
	
	-- Read from RAM
	vram_rden_sig <= '1';
	vram_rdaddress_sig <= A - x"2000";
	DI_CPU <= vram_q_sig_reg when (Wr_n = '0' and MReq_n = '0' and A >= x"2000") else
			D_ROM when (Rd_n = '0' and MReq_n = '0');
--
	vram8k_inst : work.vram8k PORT MAP (
		data	 	=> vram_data_sig,
		rdaddress	=> vram_rdaddress_sig(12 downto 0),
		rdclock	 	=> Clk_Z80,
		rden	 	=> vram_rden_sig,
		wraddress	=> vram_wraddress_sig(12 downto 0),
		wrclock		=> Clk_Z80,
		wren	 	=> vram_wren_sig,
		q	 	=> vram_q_sig
	);

It is a simple operation:

Write into RAM, Read from RAM.