Embed enforces a top-down order of execution. Therefore, if you want to write values to a hardware register in a specific order, simply arrange them from top to bottom.
When you have a combination of Extern Read and Extern Write blocks, and you require a specific order of execution, you can wire the Extern Read block to an execOrder block to control when it is executed. For example, suppose you have the following configuration:
It is ambiguous when the Extern Read block is executed. To enforce the order of execution, wire the Extern Read block into an execOrder block like so:
In this configuration, the Extern Read block will execute third.