TC1130_08 Datasheet, PDF (73/114 Pages) Infineon Technologies AG – 32-Bit Single-Chip Microcontroller

TC1130
Functional Description
3.24 Clock Generation Unit
The Clock Generation Unit (CGU) allows a flexible clock generation for TC1130. The
power consumption is indirectly proportional to the frequency, whereas the performance
of the microcontroller is directly proportional to the frequency. During user program
execution, the frequency can be programmed for an optimal ratio between performance
and power consumption. Therefore, the power consumption can be adapted to the actual
application state.
Features:
The Clock Generation Unit serves several purposes:
• PLL feature for multiplying clock source by different factors
• Direct Drive for direct clock input
• Comfortable state machine for secure switching between basic PLL, direct, or
prescaler operation
• Sleep and Power-down mode support
• USB Clock source and control
The Clock Generation Unit in the TC1130, shown in Figure 3-16, consists of an oscillator
circuit and one Phase-Locked Loop (PLL). The PLL can convert a low-frequency
external clock signal to a high-speed internal clock for maximum performance. The PLL
also has fail-safe logic that detects degenerate external clock behavior such as abnormal
frequency deviations or a total loss of the external clock. It can execute emergency
actions if it looses the lock on the external clock.
In general, the Clock Generation Unit (CGU) is controlled through the System Control
Unit (SCU) module of the TC1130.
XTAL1
XTAL2
Clock Generation Unit
CGU
Oscillator
Circuit
f_OSC
Osc.
Run
Detect.
P
Divi-
der
1
>1
Phase
Detect.
VCO
f_{VCO MUX}
0
PLL
N
Divider
Lock
Detector
1:1/1:2
Divider
K:1/K:2
Divider
MUX
f_SYS
f_CPU
Divider
f _USB
MUX
P4.0/
USBCLK
OGC MOSC OSCR
PDIV OSC PLL_
[2:0] DISC LOCK
NDIV VCO_
[6:0] SEL[1:0]
VCO_ KDIV SYS PLL_
BYPASS [3:0] FSL BYPASS
USBC USBC
LDIV LSEL
Register OSC_CON
System Control Unit
SCU
Register PLL_CLC
Figure 3-16 Clock Generation Unit Block Diagram
Register SCU_CON
MCA04940mod
Data Sheet
67
V1.1, 2008-12