Single Mpc8260 Configured From Boot Eprom; Multiple Mpc8260S Configured From Boot Eprom - Motorola MPC8260 PowerQUICC II User Manual

Part II. ConÞguration and Reset
PORESET
Vcc
Configuration
Slave Chip
HRESET
A[0Ð31]
Vcc
D[0Ð31]
PORESET
RSTCONF
Figure 5-4. Single Chip with Default Configuration
5.4.2.2 Single MPC8260 ConÞgured from Boot EPROM
For a conÞguration that differs from the default, the MPC8260 can be used as a
conÞguration master by tying RSTCONF to GND as shown in Figure 5-5. The MPC8260
can access the boot EPROM. It is assumed the conÞguration is as deÞned there upon exiting
hard reset.
PORESET
EPROM Control Signals
VCC
Boot EPROM
Configuration Master Chip
A[..]
HRESET
A[0Ð31]
D[0Ð7]
D[0Ð31]
PORESET
RSTCONF
Figure 5-5. Configuring a Single Chip from EPROM
5.4.2.3 Multiple MPC8260s ConÞgured from Boot EPROM
For a complex system with multiple MPC8260 devices that may each be conÞgured
differently, conÞguration is done by assigning one conÞguration master and multiple
conÞguration slaves. The MPC8260 that controls the boot EPROM should be the
conÞguration masterÑRSTCONF tied to GND. The RSTCONF inputs of the other
MPC8260 devices are tied to the address bus lines, thus assigning them as conÞguration
slaves. See Figure 5-6.
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