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TMS320F280023: TMS320F280023 CLB X-BAR from INPUT X-BAR

Part Number: TMS320F280023
Other Parts Discussed in Thread: SYSCONFIG

Q1: detailed datasheet TMS320F28002x: "spruin7a" page 799, TABLE 9-1 says that INPUT1 to INPUT14 (14 signals, looks like these signals are created once INPUT X-BAR is defined to respective GPIO signals) go to CLB X-BAR. Then in TABLE 9-4, page 803, I can see only INPUTXBAR1 to INPUTXBAR6 totalling 6 signals from INPUT X-BAR that can be used as input to CLB X-BAR. So, there is contradiction on 14 vs 6 signals. Please clarify.


  • Hi Sibaprasad,

    Glad to be able to help you again. It looks like the technical reference manual is out of date with our software. You are right that there is a contradiction. The correct number is 14 INPUT X-BARs that can be routed to the CLB X-BAR. I have attached a picture showing the correct muxing for each INPUTXBAR. 

    I've gone ahead and submitted a request for that to be fixed in the next iteration of the F28002x technical reference manual. 

    As a note: the image I sent comes from our SysConfig development tool which outlines the device's configuration settings in a graphical user interface. It is up-to-date and can help you understand the MUXes and resources that are available on the device.



  • Thanks Peter,

    One more confusion: page 1265, Figure 12-5, INPUT1-INPUT16 total 16 signals go to CLB BLOCK directly and treated as "Local Signals" in CLB block. Should there be a CLB OUTPUT X-BAR for peripheral block in-between that will take this 16 signals and output 8 signals. These 8 signals will go to CLB block that are designated as "External Inputs" 8 signals in page 1270, Figure 12-8. Please confirm.

  • Hi Sibaprasad, 

    I'm somewhat unclear on your question. The CLB OUTPUTXBAR is already a block but it is responsible for routing the outputs of the CLB to specific GPIO pins. It does not have anything to do with the inputs.

    The INPUT1-INPUT16 on the local signals bus refers to the CLB INPUTXBAR (different than regular INPUTXBAR and CLB XBAR) and it's responsible for bringing signals directly from GPIO into the CLB as an input. There are 16 CLB INPUTXBAR total but these are not concretely mapped to any specific CLB inputs. So you can, for example, designate CLB INPUTXBAR1 as the second input in CLB1 and then CLB INPUTXBAR2 as the fifth input in CLB2, or any combination of such. What actually goes into the CLB as inputs is decided by the input mux. 

    There is a CLB training module that we recently released in C2000 Academy that has more information about the CLB if you are interested:



  • thanks Peter, I am picking up slowly........., will be back with more question.