ELANSC310 AMD [Advanced Micro Devices], ELANSC310 Datasheet - Page 42

• Manufacturer Part Number: ELANSC310
• Description: Single-Chip, 32-Bit, PC/AT Microcontroller
• Manufacturer: AMD [Advanced Micro Devices]

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
42
LS_PLL_EN
HS_PLL_EN
VID_PLL_EN
32 kHz
Input
EN
INT_PLL
1.4746 MHz
Élan™SC310 Microcontroller Data Sheet
Figure 1. PLL Block Diagram
P R E L I M I N A R Y
EN
LS_PLL
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.
2.048 MHz
36.864 MHz
EN
VID_PLL
EN
HS_PLL
Programmable
1.1892 MHz
1.8432 MHz
14.336 MHz
2 x CPU Clock
2
18.432 MHz