mpc5645s Freescale Semiconductor, Inc, mpc5645s Datasheet - Page 61

• Manufacturer Part Number: mpc5645s
• Description: Mpc5645s Microcontroller Data Sheet
• Manufacturer: Freescale Semiconductor, Inc

3
3.1
The preferred power-up sequence for MPC5645S is as follows:
This sequence ensures that when VREG releases its LVDs, the IO and other HV segments are powered properly. This is
important because MPC5645S doesn't monitor LVDs on IO HV supplies.
Freescale Semiconductor
1.
2.
3.
4.
Generic IO supplies or noise-free supplies, consisting of:
— VDDA
— VDDE_A
— VDDE_B
— VDDM
— VDD_DR
— VDD33_DR
— VDDPLL
All 3.3V supplies (VDDE_B & VDD33_DR) should be ramped up first, and then the rest of the I/O supplies should
be ramped up (VDDA, VDDE_A, VDDM, VDD_DR).
VDDR, the regulator input supply, should be the last supply to ramp up; all supplies can be ramped up together as long
as VDDR is included. So all 5V supplies should be ramped up after the 3.3V supplies, and if all the supplies are of the
same level, they can be ramped up together as well.
LV supply (VDD12). If Vreg is in bypass mode and the core supply (1.2V) is supplied externally, then this should be
the last supply given.
System design information
Power-up sequencing
For DDR, the 3.3 V supply (VDD33_DR) should come before VDD_DR.
Analog
RSDS
SMD
DDR
Pad
M
S
F
J
MPC5645S Microcontroller Data Sheet, Rev. 6
Input/output with analog features (pad_tgate, pad_tgate_hv)
Input only with analog features (pad_ae, pad_ae_hv)
Table 6. Pad Types
NOTE
Medium (pad_msr, pad_msr_hv)
Slow (pad_ssr, pad_ssr_hv)
Stepper Motor Detector
Fast (pad_fc)
RSDS pads
DDR pads
Function
System design information
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