80960KA Datasheet, PDF (14/43 Pages) Intel Corporation – EMBEDDED 32-BIT MICROPROCESSOR

80960KA
2.3. Connection Recommendations
For reliable operation, always connect unused inputs
to an appropriate signal level. In particular, if one or
more interrupt lines are not used, they should be
pulled up. No inputs should ever be left floating.
All open-drain outputs require a pullup device. While
in most cases a simple pullup resistor is adequate, a
network of pullup and pulldown resistors biased to a
valid V_IH (>3.0 V) and terminated in the characteristic
impedance of the circuit board is recommended to
limit noise and AC power consumption. Figure 5 and
Figure 6 show recommended values for the resistor
network for low and high current drive, assuming a
characteristic impedance of 100 Ω. Terminating
output signals in this fashion limits signal swing and
reduces AC power consumption.
NOTE:
Do not connect external logic to pins marked N.C.
OPEN-DRAIN OUTPUT
V_CC
220 Ω
Low Drive Network:
V_OH = 3.0 V
I_OL = 20.7 mA
330 Ω
Figure 5. Connection Recommendations
for Low Current Drive Network
OPEN-DRAIN OUTPUT
V_CC
180 Ω
High Drive Network:
V_OH = 3.4 V
I_OL = 25.3 mA
390 Ω
Figure 6. Connection Recommendations
for High Current Drive Network
2.4. Characteristic Curves
Figure 7 shows typical supply current requirements
over the operating temperature range of the
processor at supply voltage (V_CC) of 5 V. Figure 8 and
Figure 9 show the typical power supply current (I_CC)
that the 80960KA requires at various operating
frequencies when measured at three input voltage
(V_CC) levels and two temperatures.
For a given output current (I_OL) the curve in Figure 10
shows the worst case output low voltage (V_OL). Figure
11 shows the typical capacitive derating curve for the
80960KA measured from 1.5V on the system clock
(CLK) to 1.5V on the falling edge and 1.5V on the
rising edge of the L-Bus address/data (LAD) signals.
11