AMD-762 Advanced Micro Devices, AMD-762 Datasheet - Page 36

• Manufacturer Part Number: AMD-762
• Description: System Controller
• Manufacturer: Advanced Micro Devices

AMD-762™ System Controller Data Sheet
Figure 8.
24
Generator
Clock
33 MHz (for Southbridge)
33 MHz
100/133 MHz
66 MHz
66 MHz
System Clocking with 33-MHz PCI Bus
33-MHz PCI Clocks
AGP Slot
The AMD-762 system controller implements three int e rna l
PLLs to control clock skew on-chip for the SYSCLK, AGPCLK,
and PCICLK domains. An external feedback path is required
on the motherboard for the 66-MHz PCI PLL when operating in
66-MHz mode. This requires the PCI_66CLK[0] output pin to be
connected back into the AMD-762 system controller’s PCICLK
input for skew control, as shown in Figure 7 on page 23.
These PLLs can be bypassed for motherboard testing. Refer to
Chapter 3 for further details of PLL bypass testing.
Preliminary Information
Functional Operation
PCICLK
SYSCLK
AGPCLK
AMD-762™ System Controller
AMD-766™ Peripheral
Bus Controller
Northbridge
Southbridge
32-bit, 33-MHz PCI Bus Slots
CLKOUT[1]n
CLKOUT[2]n
CLKOUT[3]n
CLKOUT[0]n
24416C—December 2001
DDR DIMMs
Chapter 2