mpc7450 Freescale Semiconductor, Inc, mpc7450 Datasheet - Page 11

• Manufacturer Part Number: mpc7450
• Description: Mpc7450 Risc Microprocessor
• Manufacturer: Freescale Semiconductor, Inc

Figure 2 shows the undershoot and overshoot voltage on the MPC7450.
The MPC7450 provides several I/O voltages to support both compatibility with existing systems and
migration to future systems. The MPC7450 core voltage must always be provided at nominal 1.6 V (see
Table 4 for actual recommended core voltage). Voltage to the L3 I/Os and processor interface I/Os are
provided through separate sets of supply pins and may be provided at the voltages shown in Table 3. The
input voltage threshold for each bus is selected by sampling the state of the voltage select pins at the negation
of the signal HRESET. The output voltage will swing from GND to the maximum voltage applied to the
OV
MOTOROLA
Notes:
1. Caution: The input threshold selection must agree with the OV
2. To select the 2.5-V threshold option for the processor bus, BVSEL should be tied to HRESET so that the two
3. Applicable to L3 bus interface only. ¬HRESET is the inverse of HRESET.
4. If used, pulldown resistors should be less than 250
BVSEL Signal
signals change state together. Similarly, to select 2.5 V for the L3 bus, tie L3VSEL to HRESET. This is the preferred
method for selecting this mode of operation.
DD
¬HRESET
HRESET
or GV
0
1
DD
OV
power pins.
OV
DD
DD
/GV
/GV
Threshold is Relative to:
GND – 0.3 V
GND – 0.7 V
MPC7450 RISC Microprocessor Hardware Specifications
OV
Processor Bus Input
DD
DD
DD
Freescale Semiconductor, Inc.
/GV
+ 20%
Not Available
+ 5%
GND
For More Information On This Product,
V
V
DD
Figure 2. Overshoot/Undershoot Voltage
Table 3. Input Threshold Voltage Setting
1.8 V
2.5 V
2.5 V
IH
IL
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.
L3VSEL Signal
Not to Exceed 10%
¬HRESET
HRESET
of t
0
1
SYSCLK
DD
/GV
Electrical and Thermal Characteristics
DD
voltages supplied. See notes in Table 2.
L3 Bus Input Threshold is
Relative to:
1.8 V
1.5 V
2.5 V
2.5 V
Notes
1, 4
1, 3
1, 2
1
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