建立时间(Setup Time)检查
Setup Time:时钟上升沿到来之前数据必须保持稳定的时间。
1:输入引脚--寄存器(pin to register)
2:寄存器--寄存器(register to register)
3:寄存器--输出引脚(register to pin)
(1):输入引脚--寄存器(pin to register)
//Clock setup slack time=Data require time—Data arrival time;
Data require time=latch edge+clock network delay to destination register—input max delay of pin;
Data arrival time=launch edge+clock network delay to source register+utco+ pin to register delay;
(2):寄存器--寄存器(register to register)
//Clock setup slack time=Data require time—Data arrival time;
Data require time=latch edge+clock network delay to destination register—utsu—(Setup uncertainty);
Data arrival time=launch edge+clock network delay to source register+utco+register to register delay;
(3):寄存器--输出引脚(register to pin)
//Clock setup slack time=Data require time—Data arrival time;
Data require time=latch edge+clock network delay to destination register—output max delay of pin;
Data arrival time=launch edge+clock network delay to source register+utco+register to pin delay;
保持时间(Hold Time)检查:
Hold Time:时钟上升沿到来之后数据必须保持稳定的时间。
1:输入引脚--寄存器(pin to register)
2:寄存器--寄存器(register to register)
3:寄存器--输出引脚(register to pin)
(1):输入引脚--寄存器(pin to register)
Clock hold time slack=Data arrival time—Data require time;
Data arrival time=launch edge+clock network delay to source register+input min delay of pin+pin to register delay;
Data require time=latch edge +clock network delay to
destination register +uth;
(2):寄存器--寄存器(register to register)
Clock hold time slack=Data arrival time—Data require time;
Data arrival time=launch edge+clock network delay to source register+utco+register to register delay;
Data require time=latch edge+clock network delay to
destination register+uth+(hold uncertain);
(3):寄存器--输出引脚(register to pin)
Clock hold time slack=Data arrival time—Data require time;
Data arrival time=launch edge+clock network delay to source register+utco+register to pin delay;
Data require time=latch edge+clock network delay to
destination register—output min delay of pin;
恢复时间(Recovery Time)检查
原则:异步控制信号变化的时刻不能介于寄存器的latch edge和相应的建立时间之间,否则会导致寄存器的建立时间违规,数据输出会进入亚稳态。
1:输入引脚—寄存器(pin to register)
2:寄存器—寄存器(register to register)
(1):输入引脚—寄存器(pin to register)
Recovery slack time=Data required time—Data arrival time;
Data required time=latch edge+clock network delay to
destination register—utsu;
Data arrival time=launch edge+Max input delay+pin to register delay;
(2):寄存器—寄存器(register to register)
Recovery slack time=Data required time—Data arrival time;
Data required time=latch edge+clock network delay to
destination register—utsu;
Data arrival time=launch edge+clock network delay to source
register+utco+register to register delay;
文章评论(0条评论)
登录后参与讨论