mpc8260aec Freescale Semiconductor, Inc, mpc8260aec Datasheet - Page 12

• Manufacturer Part Number: mpc8260aec
• Description: Mpc826xa Hip4 Family Hardware
• Manufacturer: Freescale Semiconductor, Inc

1.2.3.1
Each V
should likewise be provided with a low-impedance path to ground. The power supply pins drive distinct
groups of logic on chip. The V
by-pass capacitors located as close as possible to the four sides of the package. The capacitor leads and
associated printed circuit traces connecting to chip V
per capacitor lead. A four-layer board is recommended, employing two inner layers as V
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 5 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 6.
12
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
CC
= I
pin should be provided with a low-impedance path to the board’s power supply. Each ground pin
DD
AC Electrical Characteristics
Layout Practices
x V
Multiplier
CPM
DD
Table 5. Estimated Power Dissipation for Various Configurations
2.5
2.5
2
3
3
2
2
Watts
Core CPU
Multiplier
MPC826xA (HiP4) Family Hardware Specifications
4.5
3.5
3
3
4
3
3
CC
CC
power supply should be bypassed to ground using at least four 0.1 µF
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
CC
D
and ground should be kept to less than half an inch
= 3W (when the ambient temperature is 70˚ C or
Nominal
1.2
1.3
Vddl 1.8 Volts
—
—
—
—
—
Maximum
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
CC
1
and GND planes.
Maximum
MOTOROLA
2.3
2.3
2.9
3.1
2.8
2.8
3.1