Wrote: > One thing I do not understand is, that dout as std_logic_vector is > displayed as 'uninitialized' every other CLK-cycle - though each > individual bit of the std_logic_vector is showing a well defined logic > value.

Code: This video is part of a series which final design is a Controlled Datapath using a structural approach. A Structural approach consist in designing all components needed for the design such as gates to form subsystems and then joining them together to form a larger design like adders and Arithmetic logic units,etc. The design in these labs was first developed in VHDL you can check the final VHDL version in the link below as well as intructions on how to set up the Waveshare development board to get started, the setup is the same for VHDL and Verilog: Lab Sheets: Lab guide The complete video tutorial at: The design in this lab covers the basics of microcontrolller structural design DONATE with PAYPAL: quitoart@hotmail.co.uk Support me through Patreon! DONATE with PAYPAL: quitoart@hotmail.co.uk Support me through Patreon! Suppoert me by accessing my blog through an Ad: DONATE with BITCOIN: 1PJJiXCLqNPuQtyRebwUHdwqNJGaZsfVGt DONATE with Ethereum: 0x4671bfa4f73a6ffc5f214cf27c921b DONATE with LiteCoin: LhKtK8KEoxdpVBJLZLbEZKjjDpeHmenAPd DONATE with ZCASH: t1Md3vXgojrk5cX6jqhFpjaTWQ1fbLGFZZg.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 module piso1 (sout,sin,clk ); output sout; input [ 3: 0 ]sin; input clk; wire [ 3: 0 ]q; inv u1 (p,sl ); and1 u2 (n,sin [ 1 ],p ); and1 u3 (r,sl,q [ 0 ] ); or1 u4 (s,n,r ); and1 u5 (t,sin [ 2 ],p ); and1 u6 (u,sl,q [ 1 ] ); or1 u7 (v,u,t ); and1 u8 (w,sin [ 3 ],p ); and1 u9 (y,sl,q [ 2 ] ); or1 u10 (z,w,y ); dff1 u11 (q [ 0 ],sin [ 0 ],clk ); dff1 u12 (q [ 1 ],s,clk ); dff1 u13 (q [ 2 ],v,clk ); dff1 u14 (q [ 3 ],z,clk ); assign sout = q [ 3 ]; endmodule.