Geode NX, Bridge configurations

The following reports are applicable in Geode NX and Athlon XP-M.
The content of this page is not necessarily certain. Please confirm it by yourself.

Function of the bridges for the Mobile CPUs.

CPU Bridge number

  • L1 : It is connected from L3 to BP_FID pin.
  • L2,L9 : Level2 Cache controls
  • L3 : Start up Multipliers
  • L5 : Operation mode of CPU
  • L6 : SFID, Rated Multiplier for Mobile
  • L8 : SVID, Maximum Core voltage for Mobile
  • L11 : VID, Start up Core voltage
  • L12 : FSB auto-detection
  • Summary : About closing of the bridges

About the CPU Bridges

The allocation and the function of the bridge identification number are due to our presumption. They are not being written in the data sheet.

L1 : It is connected from L3 to BP_FID pin.

There is no problem in L1. Please leave just as it is.

Geode NX and Athlon XP-M can still change the start up multiplier. However, present Athlon XP and Sempron are locked to the ratings multiplier regardless of the state of L1.

L2 : Level2 Cache controls

There is no problem in L2 and L9. Please leave just as it is.

L2 bridge is a setting concerning the Level2 cache. And, all states of default are closed, and it is the maximum value.

OPNL2[3:0]L2 CacheProducts
ANXS1750FXC3SCCCC256kGeode NX (T-bred)
AXMH2200FQQ3CCCCC256kXP-M (T-bred)
AXMG2600FQQ4CCCCC512kXP-M (Barton)

T-bred* = Thoroughbred

L3 : Start up Multipliers

The L3 bridges are the starting multipliers. The reason that starts by 6X or 5X is in this bridge.

If the mother board doesn't have the multiplier changeing function, it is possible to change the multiplier by the L3[4:0] Bridges.

Startup Multiplier
ANXS1750FXC3SCC::C6XGeode NX 1750
ANXL1500FGC3SCC::C6XGeode NX 1500
ANXL1250FYC3SCC:CC5XGeode NX 1250
AXMH2200FQQ3CCC::C6XAthlon XP-M 2200
AXMS1600FWS3BCC:CC5XAthlon XP-M 1600

However, we know better techniques more than the processing of the bridges. Please refer to the following.
refs: Multiplier on the fly
L3 Bridges

Start up Multipliers are as follows.

5.0x 667MCC:CCMobile*1
5.5x 733MCC:C: -
6.0x 800MCC::CMobile*2
6.5x 867MCC::: -
7.0x 933MC:CCC -
7.5x1.00GC:CC: -
8.0x1.07GC:C:C -
8.5x1.13GC:C:: -
9.0x1.20GC::CC -
9.5x1.27GC::C: -
10.0x1.33GC:::C -
10.5x1.40GC:::: -
11.0x1.47GCCCCCXP 1700+
11.5x1.53GCCCC:XP 1800+
12.0x1.60GCCC:CXP 1900+
12.5x1.67GCCC::XP 2000+
13.0x1.73G:C:CCXP 2100+
13.5x1.80G:C:C:XP 2200+
14.0x1.87G:C::C -
21.0x - :C::: -
15.0x2.00G::CCCXP 2400+
22.0x - ::CC: -
16.0x2.13G::C:C -
16.5x2.20G::C:: -
17.0x2.27G:::CC -
18.0x2.40G:::C: -
23.0x - ::::C -
24.0x - ::::: -
n/a x :CCCC x
19.0x - :CCC: -
n/a x :CC:C x
20.0x - :CC:: -

C=closed ( Logic 0 ), : =open ( Logic1 )
Mobile*1 : NX1250, and the product of Mobile version with 100MHz FSB.
Mobile*2 : In general, the product of Mobile version with 133MHz FSB.
n/a : non available

Geode NX and Athlon XP-M can still change start up Multiplier by L3. If it is possible, we will recommend the Multiplier change circuit to be installed. Please refer to Barton /Multiplier circuit

L5 : Operation mode of CPU

Recognition which product it is changes with this bridge. It might have to be called product ID.


L5 [ 3 ] closed : Multiprocessing Capable
L5 [ 2 ] closed : Mobile-mode
L5 [ 1 ] opened : default ( Valid L6 value )
L5 [ 0 ] closed : default ( Valid L8 value )

If L5 [ 1 ] is opened, the ratings multiplier becomes 24X.

Operation mode of CPU
ANXS1750FXC3SCC:CGeode NXNX 1750 (T-bred)
ANXL1500FGC3SNX 1500 (T-bred)
AXMS1400FWS3BCC:CAthlon XP-MXP-M 1400+ (T-bred)
AMSN2200DKT3CC::CAthlon MPMP 2200+ (T-bred)
SDA2400DUT3DC::CSempronSempron 2400+ (T-bred)
AXDA1700DLT3C:::CAthlon XPXP 1700+ (T-bred)

It is understood that Geode NX is the same setting as Athlon XP-M.

L6 : SFID | Rated Multiplier for Mobile

The L6 bridge is FID only for mobile CPUs. The Multiplier of ratings is set in Geode NX and Athlon XP-M. This bridge is used as a limit value when it starts changing the Multiplier from software.

Cancellation of L6 multiplier
To set Multiplie in 24X of the maximum value, it only has to close L5 1. However, there are a possibility of many of boards equipped with AMI BIOS that your PC cannot be started.

5.0x 667 833CC:CCANXL1250FYC3S
5.5x 733 917CC:C: -
6.0x 8001000CC::C -
6.5x 8671083CC::: -
7.0x 9331167C:CCC -
8.0x10671333C:C:C -
8.5x11331417C:C:: -
9.0x12001500C::CC -
9.5x12671583C::C: -
10.0x13331667C:::C -
11.0x14671833CCCCCXP, Sempron
13.0x17332167:C:CC -
21.0x - - :C::: -
22.0x - - ::CC: -
16.0x21332667::C:C -
16.5x22002750::C:: -
17.0x22672833:::CC -
18.0x24003000:::C: -
23.0x - - ::::C -
24.0x - - ::::: -
3.0x 400 500 :CCCC n/a
19.0x - - :CCC: -
4.0x 533 667 :CC:C n/a
20.0x - - :CC:: -

The column of FSB 333 is a reference value. It is not ratings.

Attention with AMI BIOS

In Geode NX and Athlon XP-M, many of boards equipped with AMI BIOS start by ratings Multiplier. In this case, BIOS refers to this L6 bridge. And, it seems to set Multiplier to ratings again immediately after the start. For the mother of this type, we will recommend the Multiplier change by CrystalCPUID.

L6 are all closed in CPU of a desktop version because it is not used.

L8 : SVID | Maximum Core voltage for Mobile

In Geode NX and Athlon XP-M, L8 bridges are the same settings as L11 bridges. However, anything doesn't change even when this bridge is changed.


In the system for mobility, not only VID but also the SVID pin output is used to set the voltage. The L8 bridge seems to be used to acquire the rated voltage at this time, and to be set the maximum value of SVID.

L11 : VID | Startup Core voltage

The default core voltage is set to L11. It becomes 1.425V in automatic recognition though the rated voltage of Geode NX 1750 is 1.25V. However, it becomes 1.25V of ratings in laptop PC.

Athlon VID Code 1
Athlon XP-MAthlon XP
2.000 1.850 CCCCC
1.950 1.825 CCCC:
1.900 1.800(N)CCC:C
1.850 1.775 CCC::
1.800 1.750(M)CC:CC
1.750 1.725 CC:C:
1.700 1.700(P)CC::C
1.650 1.675 CC:::
1.600 1.650(K)C:CCC
1.550 1.625 C:CC:
1.450(Q)1.575 C:C::
1.350(J)1.525 C::C:
- 1.475 C::::
Athlon VID Code 2
Geode NX
Athlon XP-M
1.275 1.450:CCCC
1.225 1.400:CC:C
1.175 1.350:C:CC
1.125 1.300:C::C
1.075 1.250::CCC
1.050 1.225::CC:
1.025 1.200::C:C
0.975 1.150:::CC
0.950 1.125:::C:
0.925 1.100::::C
- - :::::

C shows bridge closed. Logic is 0.
: shows bridge opend. Logic is 1.

L12 : FSB | FSB setting auto-detection

In general, you may disregard this bridge. However, L12 seems to be used for FSB automatic recognition in some of mother boards. ( Example, GIGABYTE GA-7VAXP Ultra etc )

L12 [3] : closed
L12 [2] : FSB_Sense[1]
L12 [1] : closed
L12 [0] : FSB_Sense[0]

L12 FSB_Sense[1:0]
OPNL12[2]L12[0]FSB Notes
AXMD1600FQQ3B::100 MHzXP-M (T-bred)
AXDA1700DLT3C::133 MHzXP (T-bred)
AXDC2400DKV3CXP (Thorton)
ANXS1750FXC3S:C133 MHzGeode NX (T-bred)
AXMH2000FLQ3C:C133 MHzXP-M (T-bred)
AXMH2500FQQ4CXP-M (Barton)
AXDA2500DKV4DC:167 MHzXP (Barton)
AXDA3200DKV4ECC200 MHzXP (Barton)
: = open (logic level of 1) C = closed (logic level of 0)

attention : About closing of the bridges

Fundamentally, since processing of the bridge is dangerous, we cannot recommend you.
However, when you need processing of the bridges, be careful of below.

How to set the bridge of [Open] to [Close]
It is made to [Close] by using the electric conductive material.
We know the Laser pit should be filled with an insulator before anything else. In a present CPU package, it might be difficult to connect two points in the bridge. In this case, it can be solved by filling the laser pit directly with the electric conductive material.
How to set the bridge of [Close] to [Open]
The bridge is set to [Open] by cutting carefully with an edged tool.
L bridgesGeode NX, Method of closing the bridges
to GND
Insulation + closingClosing DirectlyNotes
L1It is connected from L3 to BP_FID pin.Insulated--Please maintain this state.
L2Level2 Cache controls1k Ohm--Please maintain this state.
L3Start up Multipliers1k OhmBest
(see notes)
notes : It becomes impossible to use the multiplier change function of the motherboard.
L5Operation mode of CPU0 Ohm - OptimalNo problem
L6SFID, Rated Multiplier for Mobile0 Ohm - OptimalOnly in Mobile CPUs
L8SVID, Maximum Core voltage for Mobile0 Ohm - OptimalOnly in Mobile CPUs
L9It is connected from L2 to L2_control pinInsulatedUnnecessaryNo GoodThere is no advantage usually.
L11VID, Startup Core voltage0 Ohm - OptimalNo problem
L12FSB auto-detection1k OhmBest
(see notes)
notes : It is unnecessary in a lot of mother boards.
  • Created on 04/17/2005