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XC2000 Derivatives
System Units (Vol. 1 of 2)
Preliminary
6.5
System Control Unit (SCU)
Power Supply and Control
The XC2000 can run from a single external power supply. The core supply voltages can
be generated by on-chip Embedded Voltage Regulators (EVRs) or can be fed in from an
external Voltage Regulator (VR). To significantly reduce the consumed leakage current
special power states directly considered for power saving are implemented. The major
part of the on-chip logic is located in an independent core power domain (DMP_1),
marked green and white in Figure 6-25. A second, smaller power domain (DMP_M),
marked grey, controls wake-up mechanism and other important device infrastructure
plus a Standby RAM (SB_RAM). Additionally the I/O part is divided in two parts
DMP_IO_0 and DMP_IO_1. DMP_IO_0 contains all ADC related I/Os and DMP_IO_1
the remaining system and communication I/Os. The DMP_M and/or DMP_1 can be
either switched off, i.e. disconnected from power by disabling the respective EVR1 or
lowered to 1.0 V.
The power supply and control is divided into two parts:
•
•
monitoring of the supply level
controlling and adjusting the supply level
The supply voltage of power domain DMP_IO_0 is monitored by a Supply WatchDog
(SWD, see Chapter 6.5.1).
The core voltage for each of the two core supply domains is supervised by a separate
Power Validation Circuit (PVC) that provides two monitoring levels. Each monitoring
level can request an interrupt (e.g. power-fail warning) or a reset in case of an invalid
voltage level. Device damage caused by power problems such as overcurrent due to an
external short-cut must be avoided. The PVCs are used to indicate such problems, so
together with some time-limit, the system can be protected from being damaged (see
Chapter 6.5.2).
By controlling the regulator, a core power domain can be switched off to save the
leakage current within this area (see Chapter 6.5.3.1).
Table 6-13
XC2000 Power Domains
Power Domain
Supply Source
Supply Voltage
[V]
Supply
Checked by
Pad IO domain
(DMP_IO_0)
External supply
see the data sheet
SWD
ADC IO domain
(DMP_IO_1)
External supply
see the data sheet
-
Wake-up domain
(DMP_M)
EVR_M
see the data sheet
PVC_M
System domain (DMP_1)
EVR_1
see the data sheet
PVC_1
User’s Manual
SCU, V1.1
6-90
V1.0, 2007-06