Specifications

42 Élan™SC310 Microcontroller Data Sheet
PRELIMINARY
management control (PMC) pins that are controlled by
the operating modes.
Clock Generation
The ÉlanSC310 microcontroller requires only one
32.768-kHz clock input that is used to generate all
other clock frequencies required by the system. This
32.768-kHz clock input is provided through the X32IN
and X32OUT pins and the crystal oscillator circuit. This
input frequency is then used to internally drive multiple
Phase-Locked Loops that create all necessary fre-
quencies.
The clock rate that is used to drive the internal CPU is
determined by the mode of operation of the ÉlanSC310
microcontroller.
The clock generation, control, and distribution scheme
are detailed in Figure 1 and Figure 2, which follow.
INT_PLL
LS_PLL
HS_PLL
VID_PLL
EN
32 kHz
Input
LS_PLL_EN
HS_PLL_EN
VID_PLL_EN
1.4746 MHz
18.432 MHz
1.8432 MHz
1.1892 MHz
14.336 MHz
EN
EN EN
Programmable
2 x CPU Clock
Figure 1. PLL Block Diagram
÷ 2
36.864 MHz
2.048 MHz