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Signal Integrity and Reliability of Network-on-Chip
the channel resistance of its NMOS device connecting V to GND. Figure 7.3a
shows the circuit model for the situation just described. Figure 7.3b shows
the equivalent circuit of Figure 7.3a.
From Figure 7.3b, the transfer function can be written as
V(s)
s × C
=
c
A(s) (1 Rn ) + s(C c + C v )
Hence, the voltage induced at victim node V is a function of C c and voltage
of aggressor node A.
Crosstalk delay is categorized into crosstalk slowdown and crosstalk
speedup as shown in Figure 7.2b and c, respectively. Crosstalk speedup occurs
due to same transitions in the aggressor and victim wires, whereas crosstalk
slowdown occurs due to opposite transitions in those wires. The amount
of slowdown and speedup depends on two factors: (1) input transition and
(2) skew between aggressor and victim wires. Chen et al. (1997) and Nazarian
et al. (2005) described the effect of both the parameters on crosstalk speedup
and slowdown.
At first, the effect of input transition is discussed, assuming that both signals switch simultaneously (skew = 0):
• When the slope o f t he i nput signal to the victim line i s kept constant,
faster the aggressor line changes, larger the speedup of the victim line.
• Similarly, faster aggressor causes larger worst-case slowdown.
• The maximum speedup and slowdown occur when the victim has
the largest transition time, whereas the aggressor has the smallest
transition time.
• If the transition time of both aggressor and victim wires is identical,
slow transition has lesser effect than fast transition signals.
The effect of skew between the aggressor and victim wires on crosstalk
speedup and slowdown is discussed next, assuming that both the signals
have identical transition time:
• If the input skew is negative (aggressor switches first), the amount
of speedup and slowdown increases as the skew increases from a
negative value toward zero.
• The maximum crosstalk slowdown does not necessarily occur
for zero input skew condition even for completely symmetric
interconnects.
• If the input skew increases from zero to positive direction, the
speedup and slowdown decrease. The speedup and slowdown will
become zero after some fixed positive value.
Signal Integrity and Reliability of Network-on-Chip
the channel resistance of its NMOS device connecting V to GND. Figure 7.3a
shows the circuit model for the situation just described. Figure 7.3b shows
the equivalent circuit of Figure 7.3a.
From Figure 7.3b, the transfer function can be written as
V(s)
s × C
=
c
A(s) (1 Rn ) + s(C c + C v )
Hence, the voltage induced at victim node V is a function of C c and voltage
of aggressor node A.
Crosstalk delay is categorized into crosstalk slowdown and crosstalk
speedup as shown in Figure 7.2b and c, respectively. Crosstalk speedup occurs
due to same transitions in the aggressor and victim wires, whereas crosstalk
slowdown occurs due to opposite transitions in those wires. The amount
of slowdown and speedup depends on two factors: (1) input transition and
(2) skew between aggressor and victim wires. Chen et al. (1997) and Nazarian
et al. (2005) described the effect of both the parameters on crosstalk speedup
and slowdown.
At first, the effect of input transition is discussed, assuming that both signals switch simultaneously (skew = 0):
• When the slope o f t he i nput signal to the victim line i s kept constant,
faster the aggressor line changes, larger the speedup of the victim line.
• Similarly, faster aggressor causes larger worst-case slowdown.
• The maximum speedup and slowdown occur when the victim has
the largest transition time, whereas the aggressor has the smallest
transition time.
• If the transition time of both aggressor and victim wires is identical,
slow transition has lesser effect than fast transition signals.
The effect of skew between the aggressor and victim wires on crosstalk
speedup and slowdown is discussed next, assuming that both the signals
have identical transition time:
• If the input skew is negative (aggressor switches first), the amount
of speedup and slowdown increases as the skew increases from a
negative value toward zero.
• The maximum crosstalk slowdown does not necessarily occur
for zero input skew condition even for completely symmetric
interconnects.
• If the input skew increases from zero to positive direction, the
speedup and slowdown decrease. The speedup and slowdown will
become zero after some fixed positive value.