Open-Source Ethernet MAC IP Cores for FPGAs: Overview and Evaluation
Table 10
CDC warning description.
ID
Severity
Description
CDC-1
Critical
A single-bit CDC path is not synchronized or has unknown CDC circuitry
CDC-2
Warning
A single-bit CDC path is synchronized with a 2+ stage synchronizer but the ASYNC_REG property is missing on all or some of the synchronizer flip-flops
CDC-4
Critical
A multi-bit bus CDC path is not synchronized or has unknown CDC circuitry
CDC-5
Warning
A multi-bit bus CDC path is synchronized with a 2+ stage synchronizer but the ASYNC_REG property is missing on all or some of the synchronizer flip-flops
CDC-6
Warning
A multi-bit bus CDC path is synchronized with a 2+ stage synchronizer and the ASYNC_REG property is present
CDC-7
Critical
An asynchronous signal (clear or preset) is not synchronized or has unknown CDC circuitry
CDC-10
Critical
Combinatorial logic has been detected in the fan-in of a synchronization circuit
CDC-11
Critical
A fan-out has been detected before a synchronization circuit
CDC-12
Critical
Data from multiple clocks are found in the fan-in of a synchronization circuit
