AMD-762 Datasheet, PDF (109/122 Pages) Advanced Micro Devices – System Controller

24416C—December 2001
Preliminary Information
AMD-762™ System Controller Data Sheet
Table 35. Initialization Pinstrapping (Continued)
Signal
Type
Description
CPU_Div 0
These pins define the clock multiplier for CPU 0, and are generated by the CPU. They are
used internally to create the frequency ID (FID) value, which is used in the generation of
SIP values sent to the AMD Athlon™ processor during initialization. The table below lists
the clock multipliers for each FID value.
AD[3:0]
C/BE[3]#
C/BE[2]#
C/BE[1]#
C/BE[0]
I
FID Value Multiplier FID Value Multiplier FID Value Multiplier FID Value Multiplier
0000
11.0
0100
5.0
1000
7.0
1100
9.0
0001
11.5
0101
5.5
1001
7.5
1101
9.5
0010
12.0
0110
6.0
1010
8.0
1110
10.0
0011
12.5
0111
6.5
1011
8.5
1111
10.5
The value of this pinstrap can be read in the Configuration Status register (Dev 0:F0:0x88).
Reserved
I
This pin must always have a pullup resistor installed for proper operation.
I ^Reserved
This pin must always have a pullup resistor installed for proper operation.
AGP4x Test Mode
I _{This pin should be pulled up when testing AGP in the 4x rate mode. This allows a 4x clock}
to be driven on the AGPCLK pin, and sets the appropriate internal clock dividers.
Reserved
I
This pin must always have a pulldown resistor installed for proper operation.
7.2 Pin Multiplexing
Some pin functions are multiplexed on PCI pins as described in
Table 36 on page 98 . Note that additional pin multiplexing is
required for scan testing and is described in Chapter 3. The pin
multiplexing for scan mode does not affect normal operation.
Pin multiplexing is defined for test modes only, and requires
specific PCI bus signalling pins to be pulled Low during reset
(RESET# asserted). Note that if these test functions are used on
the motherboard in lab debugging, the normal PCI signal pullup
resistors need replacing temporarily with pulldown resistors.
This action should be done only for lab testing and not in a
production environment. These signals include the following:
Chapter 7
Signal Descriptions
97