80960CF-40, -33, -25, -16
4.3 Recommended Connections
Power and ground connections must be made to
multiple VCC and VSS (GND) pins. Every 80960CF-
based circuit board should include power (VCC) and
ground (VSS) planes for power distribution. Every
VCC pin must be connected to the power plane, and
every VSS pin must be connected to the ground
plane. Pins identified as “NC” must not be
connected in the system.
Liberal decoupling capacitance should be placed
near the 80960CF. The processor can cause tran-
sient power surges when its numerous output buffers
transition, particularly when connected to large
Low inductance capacitors and interconnects are
recommended for best high frequency electrical
performance. Inductance can be reduced by short-
ening the board traces between the processor and
decoupling capacitors as much as possible. Capaci-
tors specifically designed for PGA packages will offer
the lowest possible inductance.
For reliable operation, always connect unused inputs
to an appropriate signal level. In particular, any
unused interrupt (XINT, NMI), DMA (DREQ), or
BTERM input should be connected to VCC through a
pull-up resistor. Pull-up resistors should be in the in
the range of 20 KΩ for each pin tied high. If READY
or HOLD are not used, the unused input should be
connected to ground. N.C. pins must always
remain unconnected. For additional information
refer to the i960® Cx Microprocessor User’s Manual
4.4 DC Specifications
Table 14. DC Characteristics (Sheet 1 of 2)
(80960CF-40, 33, -25, -16 under the conditions described in Section 4.2, Operating Conditions.)
VIL Input Low Voltage for all pins except RESET
VIH Input High Voltage for all pins except RESET
2.0 VCC + 0.3 V
VOL Output Low Voltage
V IOL = 5 mA
VOH Output High Voltage
IOH = –1 mA
IOH = – 200 µA VCC – 0.5
Input Low Voltage for RESET
– 0.3 1.5 V
Input High Voltage for RESET
3.5 VCC + 0.3 V
1. No pullup or pulldown.
2. These pins have internal pullup resistors.
3. These pins have internal pulldown resistors.
4. Measured at worst case frequency, VCC and temperature, with device operating and outputs loaded to the test conditions
described in Section 4.5.1, AC TEST CONDITIONS.
5. ICC Typical is not tested.
6. Output Capacitance is the capacitive load of a floating output.
7. CLKMODE pin has a pulldown resistor only when ONCE pin is deasserted.