Comparing FPGA and CPLD from various aspects

Last Update Time: 2019-07-18 10:55:11

1.Structure

The FPGA device is structurally arranged by an array of logic function blocks, and these functional blocks are connected by programmable internal wiring to realize certain logic functions.

 

FPGA :AT94S05AL-25DGI

 

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CPLDs integrate multiple programmable array logic (PAL) devices into a single chip with a PAL-like structure. In general, CPLD devices contain at least three structures: Programmable Logic Function Blocks (FB); Programmable I/O Units; Programmable Internal Connection Integration

 

CPLD:XC9536XL-5VQG44C of Xilinx Inc.

 

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FPGAs can achieve higher integration than CPLDs, as well as more complex routing structures and logic implementations.

 

FPGA is more suitable for the rich structure of flip-flops, and CPLD is more suitable for structural programming with limited trigger and rich product.

 

CPLD is programmed by modifying the logic function with fixed interconnect circuit. FPGA is mainly programmed by changing the wiring of internal wiring; FPGA can be programmed under logic gate, and CPLD is programmed under logic block. FPGA is more flexible than CPLD in programming.

 

 

2. Power consumption

The shortcomings of CPLD are more prominent. In general, CPLD power consumption is larger than FPGA, and the higher the integration, the more obvious

 

3. Speed

CPLD is better than FPGA. Because FPGAs are gate-level programming, and distributed interconnections between CLBs; CPLDs are logic block-level programming, and their logic block interconnections are lumped. Therefore, CPLD has higher speed