Appendix B. Buffering and Impedance Matching
B-1
Appendix B
Buffering and Impedance Matching
When required:
•
SDRAM and a large number of external peripherals are required for a particular
system configuration.
•
Some peripherals may have excessive input capacitance.
•
Minimize signal reflections at higher clock speeds.
•
Minimize capacitive loading on signals to SDRAMs.
•
Operation of MCF5272 at highest frequencies, i.e. 66MHz, requires clean signals
to ensure setup and hold times are met and to minimize EMC noise in terms of
overshoot and undershoot of signals.
What to do:
•
Add buffers on address and control signals shared by SDRAM and other
peripherals.
•
NEVER put buffers between the MCF5272 device and the SDRAMs.
•
Put termination resistors as close as possible to outputs.
•
Or use buffers that have integral termination resistors.
Summary of Contents for DigitalDNA ColdFire MCF5272
Page 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Page 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Page 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Page 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Page 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Page 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Page 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Page 338: ...13 44 MCF5272 User s Manual Application Examples ...
Page 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Page 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Page 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Page 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...