Hi,

I am trying to learn the datapath, verilog and the configuration tool.

I can't work out how to get an input to the ALU from the parrallel in routed fabric. According to the PSoC 5 TRM, fig 23-6 (p.154)  and fig 23-25 (p170) there is a way to source the A input to the ALU from the parallel input routing. I've enabled CFB EN in the CFGRAM, and then selected PI SEL to PIN (register CFG15-14). What I can't work out is I never see PI in the drop down for SRCA in the CFGRAM section. Do I have to manually change it in the verilog file?  I have not been able to guess what the value is (e.g. `CS_SRCA_A0 is obviously A0).

Thanks in advance.

Hello,

SRCA input to the ALU can come from either accumulator registers or Parallel In from routing fabric. The Accumulator selections are available in the SRCA dropdown for each of the 8 configuration selection of CFGRAM section in the Datapath tool.

The Parallel In (PI) can be selected as input to ALU either statically or dynamically (PSoC 5 TRM Fig 23-25, pg 170). The static operation involves setting the PI SEL bit to PIN (CFG15-14) in the Datapath configuration tool. This forces the ALU ASRC to be PI for all 8 configurations in the CFGRAM section of the datapath tool. The dynamic operation involves enabling the CFB EN bit in the CFGRAM section and enabling PI DYN bit in CFG15-14 of the datapath tool. The CFB EN bit is set on each of the 8 configurations available in CFGRAM section.

Note the SRCA input drop down selection in the CFGRAM section will have no bearing on the SRCA input if PI SEL or PI DYN (with CFB EN bit set) is enabled to use Parallel In selection. You can verify the selections by looking at the verilog file generated by the Datapath Configuration tool. For example, the verilog file will indicate an Accumulator or PI selection by the following line - 

Accumulator Selection - `SC_A0_SRC_ACC

PI Selection  -`SC_A0_SRC_PIN

--Sathya

Please note that the dynamic Parallel Input operation is not supported with PSoC 5.

Sathya

 Please note that the dynamic Parallel Input operation is not supported with PSoC 5.

Sathya

Thanks for your answers. 

to clarify:

for PSoC 5 it is not possible to use the  PI dynamic operation as indicated in the TRM?

therefore, in order to use parallel input do I have to select the CFB EN bit in all 8 configurations for the CFGRAM? 

Please note that the dynamic Parallel Input operation is not supported with PSoC 5.

Sathya

where do you have this information from? This would be really silly for me

Is the PI supported in PSoC5LP ?

Bob

Sathya

Thx, Sathya!

Bob