Huawei Mediapad S7-PRO Maintenance Manual page 42

Mediapad power-on sequence:
Standard sequence:
VREG_S0A--->VREG_S1A--->VREG_S3A--->VREG_S2A--->VREG_L0A--->VREG_L21
A--->VREG_L7A--->VREG_L13A--->VREG_L16A--->VREG_L5A--->VREG_L6A--->VR
EG_S0B--->VREG_S3B--->VREG_L3B--->VREG_L11A--->--->TP_3V3--->VREG_L4B
1. VDD_MEM (internal memory)
2. VDD_C1 (digital core circuits)
3. VDD_ISM1 and VDD_P3 (ISM 1.8 V power and most pad circuits/peripheral I/Os
respectively)
4. VDD_A3 (1.3 V RF, GPS ADC)
5. VDD_A2 (MIPI-DSI display)
6. VDD_A1, VDD_PXO, and VDD_MXO (PLLs, PXO, and MXO crystal power
respectively)
7. VDD_USBPHY_1P8 (1.8 V USB supply)
8. VDD_A5 (DACs and BBRx)
9. VDD_A4; VDD_A4_GPLL and VDD_A4_HFPLL (HDMI and MIPI-CSI; PLLs)
10. VDD_P2 (2.85 V SD card)
11. VDD_USBPHY_3P3 (3.3 V USB supply)
12. VDD_SC1 (1.1 V Scorpion core 1 – optional)
NOTE
1. The core voltage (VDD_C1) needs to be powered up before the pad circuits
2. If pad voltages are powered up first, the output drivers may be stuck in unknown
3. The pad voltages must precede the analog voltages (VDD_AX), because the SSBIs
4. VDD_QDSP, VDD_SC1, and VDD_SC2 (QDSP and Scorpion core circuits) can be
5. Other non-critical supplies are included in the power-up sequence. Any other desired
6. Each domain needs to reach the 90% value before the next domain starts ramping up.
2012-07-20
S7-PRO Maintenance Manual (Basic Version V2.1)
(VDD_PX) are powered up, so that internal circuits can take control of the I/Os and
pads.
states, and may cause high leakage current until VDD_C1 is powered on.
are initialized to the default state before VDD_AX is powered up (analog circuits are
controlled by SSBI).
powered up by the software after the MSM device has completed the boot process.
supplies can be powered up by software after the sequence is completed.
For example, when VDD_C1 reaches 90% of the specified value, the VDD_P3 supply
can start ramping up.
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