5.9.1.1 Power-Up Sequence
Figure 5-3 describes the Power-Up Sequencing of the device.
- Power-up begins by asserting PORn and applying DVDD33 first.
- PORn shall be asserted before the power-up sequence begins and held until all power supplies are within their specified recommended operating range.
- Oscillator Power‐up time defines where SYSOSC may start oscillation and the time required for oscillation to become stable, which is a function the crystal circuit components selected.
- BOOTMODE pins are synchronously latched after the rising edge of PORn using SYSOSC_IN or SYSCLK_P / N with setup and hold timing requirements defined in Table 5-15, Boot Configuration Timing Requirements.
- RESETSTATn and BOOTCOMPLETE are outputs and only shown for informational purposes.
- SYSOSC_IN or SYSCLK_P/N reference clock shall be valid at least 2 ms before PORn is released.
- If externally sourced, must be present prior to PORn.
- The VPP2 power supply pin is only valid for high-security (66AK2G1xS) devices. The VPP2 power source shall only be enabled while programming the customer OTP eFuse array and shall be disabled during power-up sequence, normal operation, and power-down sequence. When disabled, the power source shall not source current to, or sink current from the VPP2 terminal. This power supply pin is reserved for general purpose (66AK2G1x) devices and shall not be connected to any signal, test point, or printed circuit board trace when using 66AK2G1x devices.
- The SYSCLKSEL must be driven to the appropriate and valid logic level at least 500ns before the rising edge of PORn, then held at the same logic level as long as the device is operational.