MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 4-1
Chapter 4 System Interface Unit (SIU)
The system interface unit (SIU) consists of several functions that control system start-up and initialization,
as well as operation, protection, and the external system bus. Key features of the SIU include the
following:
System configuration and protection
System reset monitoring and generation
Clock synthesizer
Power management
60x bus interface
Flexible, high-performance memory controller
Level-two cache controller interface
PCI interface (MPC8250, MPC8265, and MPC8266 only)
IEEE 1149.1 test-access port (TAP)
Figure 4-1 is a block diagram of the SIU.
Figure 4-1. SIU Block Diagram
The system configuration and protection functions provide various monitors and timers, including the bus
monitor, software watchdog timer, periodic interrupt timer, and time counter. The clock synthesizer
60x Bus (32-Bit Address/64-Bit Data)
Memory
Controller
Core
Control
Memory
Controller
Local
Control
Local Bus (18-Bit Address/32-Bit Data)
Bridge
Core
Communications
Processor
ConfigurationRegisters
Counters
Interrupt
Controller