Motorola MPC8260 - Manual (Page 194)

5-10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA
Part II. ConÞguration and Reset
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.
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.
Configuration
Slave Chip
PORESET
PORESET
RSTCONF
D[0Ð31]
A[0Ð31]
HRESET
Vcc
Vcc
Configuration Master Chip
PORESET
PORESET
Boot EPROM
EPROM Control Signals
RSTCONF
D[0Ð31]
D[0Ð7] A[0Ð31]
A[..] HRESET
VCC
Address Bus
Data Bus