AMD Sempron™ Processor Model 10 with 256K L2 Cache Data Sheet

31994A—1 August 2004

FID[3:0] Pins

FID[3] (Y3), FID[2] (Y1), FID[1] (W3), and FID[0] (W1) are the

 

4-bit processor clock-to-SYSCLK ratio.

 

Table 21 describes the encodings of the clock multipliers on

 

FID[3:0].

Table 21. FID[3:0] Clock Multiplier Encodings

FID[3:0]2

Processor Clock to SYSCLK Frequency Ratio

0000

11

 

 

0001

11.5

 

 

0010

12

 

 

0011

12.51

0100

5

 

 

0101

5.5

 

 

0110

6

 

 

0111

6.5

 

 

1000

7

 

 

1001

7.5

 

 

1010

8

 

 

1011

8.5

 

 

1100

9

 

 

1101

9.5

 

 

1110

10

 

 

1111

10.5

 

 

Notes:

1. All ratios greater than or equal to 12.5x have the same FID[3:0] code of 0011b, which causes the SIP configuration for all ratios of 12.5x or greater to be the same.

2. BIOS initializes the CLK_Ctl MSR during the POST routine. This CLK_Ctl setting is used with all FID combinations and selects a Halt disconnect divisor and a Stop Grant disconnect divisor. For more information, refer to the AMD Athlon™ and AMD Duron™ Processors BIOS, Software, and Debug Developers Guide, order# 21656.

The FID[3:0] signals are open-drain processor outputs that are pulled High on the motherboard and sampled by the chipset to determine the SIP (serial initialization packet) that is sent to the processor. The FID[3:0] signals are valid after PWROK is asserted. The FID[3:0]signals must not be sampled until they become valid. See the AMD Athlon™ and AMD Duron™ System Bus Specification, order# 21902 for more information about Serialization Initialization Packets and SIP protocol.

The processor FID[3:0] outputs are open-drain and 2.5-V tolerant. To prevent damage to the processor, do not pull these

70

Pin Descriptions

Chapter 10

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Image 82
AMD 10 manual FID30 Pins, FID30 Clock Multiplier Encodings