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MPC7448 RISC Microprocessor Hardware Specifications, Rev. 4

16 Freescale Semiconductor

Electrical and Thermal Characteristics

Notes:

1. Caution: The SYSCLK frequency and PLL_CFG[0:5] settings must be chosen such that the resulting SYSCLK (bus)

frequency, processor core frequency, and PLL (VCO) frequency do not exceed their respective maximum or minimum

operating frequencies. Refer to the PLL_CFG[0:5] signal description in Section 9.1.1, “PLL Configuration,” for valid

PLL_CFG[0:5] settings.

2. Actual maximum system bus frequency is system-dependent. See Section 5.2.1, “Clock AC Specifications.”

3. Rise and fall times for the SYSCLK input measured from 0.4 to 1.4 V

4. Timing is guaranteed by design and characterization.

5. Guaranteed by design

6. The SYSCLK driver’s closed loop jitter bandwidth should be less than 1.5 MHz at –3 dB.

7. Relock timing is guaranteed by design and characterization. PLL-relock time is the maximum amount of time required for PLL

lock after a stable V

and SYSCLK are reached during the power-on reset sequence. This specification also applies when

the PLL has been disabled and subsequently re-enabled during sleep mode. Also note that HRESET

must be held asserted

for a minimum of 255 bus clocks after the PLL-relock time during the power-on reset sequence.

8. This reflects the maximum and minimum core frequencies when the dynamic frequency switching feature (DFS) is disabled.

core_DFS

provides the maximum and minimum core frequencies when operating in a DFS mode.

9.This specification supports the Dynamic Frequency Switching (DFS) feature and is applicable only when one of the DFS modes

(divide-by-2 or divide-by-4) is enabled. When DFS is disabled, the core frequency must conform to the maximum and minimum

frequencies stated for f

core

10.Use of the DFS feature does not affect VCO frequency.

Table 8. Clock AC Timing Specifications

At recommended operating conditions. See Table 4.

Characteristic Symbol

Maximum Processor Core Frequency (Speed Grade)

Unit Notes1000 MHz 1420 MHz 1600 MHz 1700 MHz

Min Max Min Max Min Max Min Max

Processor

core

frequency

DFS mode disabled f

core

600 1000 600 1420 600 1600 600 1700 MHz 1, 8

DFS mode enabled f

core

300 500 300 710 300 800 300 850 9

VCO frequency f

VCO

600 1000 600 1420 600 800 600 1700 MHz 1, 10

SYSCLK frequency f

SYSCLK

33 200 33 200 33 200 33 200 MHz 1, 2, 8

SYSCLK cycle time t

SYSCLK

5.0 30 5.0 30 5.0 30 5.0 30 ns 2

SYSCLK rise and fall time t

, t

—0.5—0.5—0.5—0.5ns 3

SYSCLK duty cycle measured at

KHKL

SYSCLK

40 60 40 60 40 60 40 60 % 4

SYSCLK cycle-to-cycle jitter — 150 — 150 — 150 — 150 ps 5, 6

Internal PLL relock time — 100 — 100 — 100 — 100 μs7

1 2 ... 11 12 13 14 15 16 17 18 19 20 21 ... 59 60

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