MAX7000S interconnect fabric In Altera’s MAX7000S CPLD family, all device inputs and all macrocell outputs feed which on-chip resource that distributes signals for logic implementation?

Difficulty: Easy

Correct Answer: PIA

Explanation:


Introduction / Context:
Complex PLDs (CPLDs) like MAX7000S use a centralized interconnect matrix to route signals among macrocells and I/O pins. Knowing the correct name and role of this resource helps you interpret fitter reports and timing analyses.



Given Data / Assumptions:

  • MAX7000S devices are CPLDs with product-term macrocells rather than LUT-based logic.
  • They use a Programmable Interconnect Array (PIA) to connect signals across the device.
  • “Macrocell outputs” and “inputs” are both sources into this interconnect.


Concept / Approach:
In these CPLDs, the PIA is the switching matrix that receives all inputs (from pins and internal sources) and macrocell outputs, then forwards them to the appropriate product-term arrays of destination macrocells. This is distinct from the FPGA notion of LABs/LUTs used in FLEX families.



Step-by-Step Solution:

Identify the architecture: CPLD with macrocells and PIA.Recognize that all external inputs and internal macrocell outputs must be routable.The dedicated resource that collects and redistributes these is the PIA.Hence, the correct answer is PIA.


Verification / Alternative check:
The block diagram in the MAX7000S handbook shows the PIA as the central switching fabric connecting I/O pins and macrocells.



Why Other Options Are Wrong:
“LUT” refers to FPGA logic organization, not used in MAX7000S. “LAB” is an FPGA grouping; CPLDs instead use function blocks with a PIA. “PIA and LAB” mixes CPLD and FPGA terms inaccurately.



Common Pitfalls:
Transferring FPGA terminology to CPLDs; while both are programmable, their internal fabrics are different.



Final Answer:
PIA

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