Okay, I'm summarizing the key information from the provided document extract. This is a snippet from the hardware specification for the MPC8308 processor, focusing on electrical characteristics.

Overall Context: The document details electrical specifications for the MPC8308 processor and its related interfaces, especially DDR2 SDRAM. It defines voltage levels, current limits, timing requirements, and capacitance values to ensure proper operation.

Key Sections & Summaries:

1. Reset Initialization:
️· HRESET & PORESET: Defines timings and voltage levels for the hardware reset signals. These are critical for initialization.
- Required assertion time for HRESET is 32 * tSYS_CLK_IN
- Time for the device to turn off POR configuration signal drivers with respect to the assertion of HRESET is 4 ns
️· PLL Lock Times: Specifies how long the system and core PLLs take to lock, indicating initialization stability.
- System PLL Lock Time: 100 μs
- e300 Core PLL Lock Time: 100 μs

2. DDR2 SDRAM Interface:
️· Voltage Levels (GV DD = 1.8V): Defines the allowed voltage ranges for the DDR2 SDRAM signals.
- GVDD (I/O Supply): 1.7V to 1.9V
- MVREF (Reference Voltage): 0.49 * GVDD to 0.51 * GVDD
️· Current Limits: Defines maximum output current in both high and low states.
- Output high current: -13.4 mA to -

- Output low current: 13.4 mA
️· Capacitance Values: Provides capacitance figures for I/O signals.
- Input/output capacitance (DQ, DQS): 6 to 8 pF
- Delta capacitance: 0 to 0.5 pF

Important Notes & Constraints:

️· Voltage Tracking: GV DD (DDR2) should stay within 50mV of the processor's GV DD.
️· MVREF Stability: MVREF should track GV DD changes and have minimal noise.
️· Termination: VTT, the termination voltage, is important for signal integrity and should track MVREF.
️· tSYS_CLK_IN: A critical timing parameter representing the input clock period. Used in calculating many reset and initialization timings.
️· Peak-to-Peak Noise: Peak-to-peak noise on MVREF may not exceed ±2% of the DC value.



This summary highlights the most important electrical parameters and constraints outlined in the provided document extract. It provides a good overview for engineers working with the MPC8308 and its DDR2 memory interface.