human
Write me a the Python code you requested given the following:
I am working on the file "PYNQLearn/FabricOnly/.ipynb_checkpoints/myHDL_PYNQZ12_FabricOnly-checkpoint.ipynb".
The first task is:
\begin{figure}
\centerline{\includegraphics[width=10cm]{S2L4_RTL.png}}
\caption{\label{fig:S2L4RTL} S2L4 RTL schematic.
Xilinx Vivado 2017.4}
\end{figure}
\begin{figure}
\centerline{\includegraphics[width=10cm]{S2L4_SYN.png}}
\caption{\label{fig:S2L4SYN} S2L4 Synthesized Schematic.
Xilinx Vivado 2017.4}
\end{figure}
\begin{figure}
\centerline{\includegraphics[width=10cm]{S2L4_IMP.png}}
\caption{\label{fig:S2L4SYN} S2L4 Implementated Schematic.
Xilinx Vivado 2017.4}
\end{figure}
Verilog Testbench (ToDo)
will write later when testbench conversion is improved
PYNQ-Z1 Constraints File
using same one as in 1 Switch 1 LED: constrs_S0L0.xdc
Board Verification
Project 3: Countdown
myHDL Code
Can you write Python code for it?
assistant
#Here is the Python code you requested.

@block
def countLED(clk, led):
    counter=Signal(modbv(0)[33:])
    
    @always(clk.posedge)
    def logic():
        counter.next=counter+1
        led.next[0]=counter[26]
        led.next[1]=counter[24]
        led.next[3]=counter[22]
        led.next[4]=counter[20]
    
    return instances()