abdel0721
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I read a lot of posts about set_drive command on DC.
From DC and PT User Guide I found that:
1: Drive strength is the reciprocal of the output driver resistance, and the transition time delay at an input port is the product of the drive resistance and the capacitance load of the input port.
2: By default, Design Compiler assumes zero drive resistance on input ports, meaning infinite drive strength.
3: For heavily loaded driving ports, such as clock lines, keep the drive strength setting at 0 so that Design Compiler does not buffer the net. (CLK, RESET). So, set_drive = 0
So far now pretty clear, my doubt is as follows:
If I want to specify the drive strength of my top level ports, which are driven by an external device, and I assume 50 Ohm impedance line (external driver + board trace matched), should I specify set_drive = 50 ???
I found no reference about values other than '0', in any document or posts.
Thanks in advance for your support
From DC and PT User Guide I found that:
1: Drive strength is the reciprocal of the output driver resistance, and the transition time delay at an input port is the product of the drive resistance and the capacitance load of the input port.
2: By default, Design Compiler assumes zero drive resistance on input ports, meaning infinite drive strength.
3: For heavily loaded driving ports, such as clock lines, keep the drive strength setting at 0 so that Design Compiler does not buffer the net. (CLK, RESET). So, set_drive = 0
So far now pretty clear, my doubt is as follows:
If I want to specify the drive strength of my top level ports, which are driven by an external device, and I assume 50 Ohm impedance line (external driver + board trace matched), should I specify set_drive = 50 ???
I found no reference about values other than '0', in any document or posts.
Thanks in advance for your support