Chapter 7 Power and Signal Distribution
7.3.2 LOW VOLTAGE PRODUCTION/DISTRIBUTION
Voltages less than 3.3 VDC including processor core (VCore) voltage are produced through regulator circuitry (Figure
Power Supply
+12.8 VDC
+5 AUX
+3.3 VDC
3.3
Auxiliary
Circuit
3.3 AUX
3.3 AUX
1.5 / 1.4
Regulator
Circuit
1.2
Auxiliary
Circuit
DDR
S3 PWR
Circuit
3.3 AUX [1]
DIMMs
1.2AUX Chipset
2.6VDC
+1.3 VDC | DDR DIMMs |
+1.5 VDC |
|
+1.4 VDC | Chipset |
| |
+12 VDC |
|
+5 VDC
VID0
VID1
ProcessorVID2 VID3
VID4
Regulator
Circuit
PWM A
+12.8 VDC
PWM B
+12.8 VDC
PWM C
+12.8 VDC
Driver Circuit A
Driver Circuit B
Driver Circuit C
MOSFET |
Finals |
Processor
VCore
Figure 7-4. Low Voltage Supply and Distribution Diagram
The regulator produces the VCore (processor core) voltage according to the strapping of signals VID4..0 by the processor. The possible voltages available are listed as follows:
VID 4..0 | VCore |
00000 | 1.850 |
00001 | 1.825 |
00010 | 1.800 |
00011 | 1.775 |
00100 | 1.750 |
00101 | 1.725 |
00110 | 1.700 |
00111 | 1.675 |
01000 | 1.650 |
01001 | 1.625 |
01010 | 1.600 |
VID 4..0 | VCore |
01011 | 1.575 |
01100 | 1.550 |
01101 | 1.525 |
01110 | 1.500 |
01111 | 1.475 |
10000 | 1.450 |
10001 | 1.425 |
10010 | 1.400 |
10011 | 1.375 |
10100 | 1.350 |
10101 | 1.325 |
VID 4..0 | VCore |
10110 | 1.300 |
10111 | 1.275 |
11000 | 1.250 |
11001 | 1.225 |
11010 | 1.200 |
11011 | 1.175 |
11100 | 1.150 |
11101 | 1.125 |
11110 | 1.100 |
11111 | Off |
Second Edition - April 2003