MPC8247VR datasheet(22/61 Pages) FREESCALE

22 / 61 page

MPC8272 PowerQUICC II Family Hardware Specifications, Rev. 3

Freescale Semiconductor

AC Electrical Characteristics

This figure shows PIO and timer signals.

Figure 8. PIO and Timer Signal Diagram

6.2

SIU AC Characteristics

This table lists SIU input characteristics.

NOTE: CLKIN Jitter and Duty Cycle

The CLKIN input to the SoC should not exceed +/– 150 psec of jitter

(peak-to-peak). This represents total input jitter—the combination of short

term (peak-to-peak) and long term (cumulative). The duty cycle of CLKIN

should not exceed the ratio of 40:60.

NOTE: Spread Spectrum Clocking

Spread spectrum clocking is allowed with 1% input frequency down-spread

at maximum 60 KHz modulation rate regardless of input frequency.

NOTE: PCI AC Timing

The SoC meets the timing requirements of PCI Specification Revision 2.2.

See Section 7, “Clock Configuration Modes,” and “Note: Tval (Output

Hold)” to determine if a specific clock configuration is compliant.

Sys clk

PIO/IDMA/TIMER[TGATE assertion] input signals

IDMA output signals

sp22

sp23

sp42/sp43

TIMER(sp42/43)/ PIO(sp42a/sp43a)

sp42a/sp43a

output signals

sp42/sp43

TIMER input signal [TGATE deassertion]

sp22

sp23

Note: TGATE is asserted on the rising edge of the clock; it is deasserted on the falling edge.

(See note)

MPC8247VR Datasheet(PDF) 22 Page - Freescale Semiconductor, Inc