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qd0090
Beginner
42 Views

question about the fmax in timequest

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i use 10m02DCV36C8G,  my clock is 96MHz(generate by pll)

i constraint the clk in timequest, and the time quest shows 

in slow 1200mV 85C model   the Fmax is 119.6MHz

1. does it means

in condition of slow 1200mV 85C 

the design can reach Fmax?  (which is 119.6 MHz)

in this case, there is still margin for my design(119.6MHz>96MHz), can the  10m02DCV36C8G work in higher temperature? like 90C?

 

2. if the what will happen if the Tj>85C?

 

3. since the Tj is  not the environment temperature

how can i know the Tj?

i mean the Tj may > 85C when environment temperature is 60C

 

 

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1 Solution
Ash_R_Intel
Employee
28 Views

Hi,

1) Yes, at slow 1200mV and 85C, the design can functionally operate at max 119.6MHz.

There are different junction temperature ranges available for which you can calculate the Fmax.

Go to Assignments -> Settings -> Temperature.

At the top, you can specify the Junction temperature range. Under Maximum temperature, you can choose upto 125 C. Closest higher value to 90c will be 100C.

You can vary this value and run the timing analyzer to get the Fmax values for a particular model defined by the temperature settings.


2) At Tj > 85C, the functional timing may change. The operating frequency can be estimated by choosing wider range of temperature as explained in point#1.


3) In the same Settings page, you have option to Auto compute junction temperature. Specify the Ambient temp value and other settings. Once set, run the Assembler task. Then go to Processing -> Power Analyzer Tool to get the auto-computed value of junction temperature.


Hope this helps.


Regards.


View solution in original post

2 Replies
Ash_R_Intel
Employee
29 Views

Hi,

1) Yes, at slow 1200mV and 85C, the design can functionally operate at max 119.6MHz.

There are different junction temperature ranges available for which you can calculate the Fmax.

Go to Assignments -> Settings -> Temperature.

At the top, you can specify the Junction temperature range. Under Maximum temperature, you can choose upto 125 C. Closest higher value to 90c will be 100C.

You can vary this value and run the timing analyzer to get the Fmax values for a particular model defined by the temperature settings.


2) At Tj > 85C, the functional timing may change. The operating frequency can be estimated by choosing wider range of temperature as explained in point#1.


3) In the same Settings page, you have option to Auto compute junction temperature. Specify the Ambient temp value and other settings. Once set, run the Assembler task. Then go to Processing -> Power Analyzer Tool to get the auto-computed value of junction temperature.


Hope this helps.


Regards.


View solution in original post

qd0090
Beginner
20 Views

thank you 

i get all i need

Reply