Now that all the design work has been done for the square root component, we can do the work of creating the component in the tool. First, create a new project in PSoC Creator. Then, create a new component by right clicking your project in the Components tab, selecting "Add Component Item..." and selecting "Verilog File":
Now, load up the Datapath Configuration Tool and open the Verilog file that was created in the previous step. Select Edit->New Datapath. Choose the Instance Type to be cy_psoc3_dp8, give it a name, and click OK.
This will create a single 8-bit datapath with all of the default settings. Now we can configure the CFGRAM to implement our 8 operations. I've highlighted the important entries for each operation, as well as any that changed from the default:
Now we can configure the static portion of the datapath configuration. There isn t much to do here. We need to make sure that our comparison is configured correctly, and that both FIFOs have dynamic mode enabled. Everything else can stay with the default values.
Now, save the file and close the Datapath Configuration tool. The last step is editing the Verilog file to add the state machine parameter values from the last blog post, the actual state machine and a few other pieces of Verilog to complete the logic of the component.
We'll define a few more control signals: A fifo_dyn wire to determine when the FIFOs are CPU/DMA-controlled vs. datapath-controlled, an eoc wire to indicate when computation has completed, and a cs_addr wire to dynamically select the operation. Note that this is simply the lower 3 bits of the state. We'll also need wires for each of the two conditions that we plan on using in the state machine:
The state machine is relatively simple. It can be pieced together from the state diagram:
Finally, we need to hook up our control and condition wires to the datapath:
We now have a component that configures the datapath to compute the square root of an 8-bit number. In the CJCU_Isqrt component, CJ has extended this implementation to 16, 24, and 32 bits, as well as providing APIs. For information on how to extend datapath functionality to multiple bytes, see PSoC Creator 213. To see how to design component APIs for datapath components, see PSoC Creator 214.