AR# 38301: CoolRunner-II Timing - Is the tCYC of a dual edge trigger register correctly analyzed?
AR# 38301
CoolRunner-II Timing - Is the tCYC of a dual edge trigger register correctly analyzed?
Description
Is the tCYC of a dual edge trigger register correctly analyzed?
Solution
The definition of the Clock to Setup (tCYC) in the CPLD timing report states: Register to register cycle time. Includes source register tCO and destination register tSU. NOTE: When the computed Maximum Clock Speed is limited by tCYC, it is computed assuming that all registers are rising-edge sensitive. Therefore, when you are using a dual edge trigger register, the tCYC only takes the rising-edge into account.