MAX7000 family basics In the Altera/Intel MAX7000 family, how many macrocells does a single LAB (Logic Array Block) contain?
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A8
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B16
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C32
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D64
Answer
Correct Answer: 16
Explanation
Introduction / Context:Understanding the granular resources of CPLD families like MAX7000 helps with capacity planning, fitting, and timing. The LAB (Logic Array Block) is a fundamental grouping unit in these devices, containing a fixed number of macrocells that share product terms and routing resources.
Given Data / Assumptions:
- MAX7000 devices are EEPROM-based CPLDs with macrocells grouped into LABs.
- Design tools report resource usage in macrocells and LABs.
- We are focusing on the standard LAB composition for the MAX7000 family.
Concept / Approach:In MAX7000-class devices, each LAB contains 16 macrocells. A macrocell typically includes a register (flip-flop), product-term allocator, and output control allowing registered or combinational operation. Knowing “16 per LAB” lets you quickly estimate how many LABs your equations will occupy given a macrocell count, and whether cross-LAB product-term routing might be required.
Step-by-Step Solution:
Recall MAX7000 architecture: EEPROM configuration with LAB-based organization.Remember the standard per-LAB macrocell count: 16.Use this figure for early sizing (for example, a 128-macrocell design needs about 8 LABs).Consider fit implications (product-term sharing and pin/IOB constraints) beyond raw counts.Verification / Alternative check:Architecture overviews and datasheets consistently show 16 macrocells per LAB in MAX7000 series CPLDs.
Why Other Options Are Wrong:
- 8/32/64: Do not match the MAX7000 LAB organization; these numbers are typical of other device families or different grouping constructs.
Common Pitfalls:Assuming FPGA-style LAB/CLB counts map directly to CPLDs; CPLDs use product-term logic with different packing behavior compared to LUT-based FPGAs.
Final Answer:16