XC2200 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
User’s Manual
6-1
V2.1, 2008-08
SCU, V1.13
6
System Control Unit (SCU)
The System Control Unit (SCU) of the XC2200 handles all system control tasks besides
the debug related tasks which are controlled by the OCDS/Cerberus. All functions
described in this chapter are tightly coupled, thus, they are conveniently handled by one
unit, the SCU.
The SCU contains the following functional sub-blocks:
•
Clock Generation (see
)
•
Wake-up Timer (see
•
Reset Operation (see
)
•
External Service Requests (see
)
•
Power Supply and Control (see
)
•
Global State Control (see
)
•
Software Boot Support (see
)
•
External Request Unit (see
)
•
Interrupt Generation (see
)
•
Temperature Compensation (see
•
Watchdog Timer (see
)
•
Trap Generation (see
)
•
Memory Content Protection (see
)
•
Register Access Control (see
)
•
Miscellaneous System Registers (see
•
SCU Registers and Address map (see
Important Information: Register Programming
The System Control Unit contains special function registers, which can not be
programmed in an arbitrary order in particular due to the usage of an internal voltage
regulator and power saving modes. In order to prevent critical system conditions
because of an improper setup and to provide means for easy and quick configuration
and control of sensitve features such as power supply and clock generation,
recommendations and examples for the programming sequence of the registers will be
given in the Programmer’s Guide.
In particular the registers listed below have to be updated with care:
•
Clock Generation Unit: WUOSCCON, HPOSCCON, PLLOSCCON, PLLCONx
•
Power Supply: EVR1CON0, EVR1SET10V, EVR1SET15VLP, EVR1SET15VHP,
EVRMCON0, EVRMSET10V, EVRMSET15VLP, EVRMSET15VHP,
PVC1CON0, PVCMCON0,
SWDCON0, SEQCON
•
System: STEP0, SYSCON0