MPC8260A Motorola, MPC8260A Datasheet - Page 13

• Manufacturer Part Number: MPC8260A
• Description: Micro Processor
• Manufacturer: Motorola

All output pins on the MPC826xA have fast rise and fall times. Printed circuit (PC) trace interconnection
length should be minimized in order to minimize overdamped conditions and reflections caused by these
fast output switching times. This recommendation particularly applies to the address and data buses.
Maximum PC trace lengths of six inches are recommended. Capacitance calculations should consider all
device loads as well as parasitic capacitances due to the PC traces. Attention to proper PCB layout and
bypassing becomes especially critical in systems with higher capacitive loads because these loads create
higher transient currents in the V
during reset. Special care should be taken to minimize the noise levels on the PLL supply pins.
Table 7 provides preliminary, estimated power dissipation for various configurations. Note that suitable
thermal management is required for conditions above P
greater) to ensure the junction temperature does not exceed the maximum specified value. Also note that the
I/O power should be included when determining whether to use a heat sink.
1.2.4
The following sections include illustrations and tables of clock diagrams, signals, and CPM outputs and
inputs for the 66 MHz MPC826xA device. Note that AC timings are based on a 50-pf load. Typical output
buffer impedances are shown in Table 8.
MOTOROLA
1
2
Test temperature = room temperature (25
P
(MHz)
66.66
66.66
66.66
66.66
83.33
83.33
83.33
INT
Bus
= I
DD
AC Electrical Characteristics
x V
Multiplier
CPM
DD
Table 7. Estimated Power Dissipation for Various Configurations
2.5
2.5
2
3
3
2
2
Watts
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
1
60x bus
Local bus
Memory controller
Parallel I/O
PCI
These are typical values at 65˚ C. The impedance may vary
by ±25% with process and temperature.
Core CPU
Multiplier
MPC826xA (HiP4) Family Hardware Specifications
Output Buffers
4.5
3.5
3
3
4
3
3
CC
Table 8. Output Buffer Impedances
and GND circuits. Pull up all unused inputs or signals that will be inputs
(MHz)
CPM
133
166
200
200
166
166
208
˚
C)
(MHz)
CPU
200
200
266
300
250
250
291
D
Typical Impedance (Ω)
= 3W (when the ambient temperature is 70˚ C or
Nominal
1.2
1.3
—
—
—
—
—
Vddl 1.8 Volts
Electrical and Thermal Characteristics
40
40
40
46
25
Maximum
1
2.1
—
—
—
—
—
2
P
INT
(W)
Nominal
2
1.8
1.9
2.3
2.4
2.2
2.2
2.4
Vddl 2.0 Volts
1
Maximum
2.3
2.3
2.9
3.1
2.8
2.8
3.1
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