1 |
Begin Power Stabilization Phase
- Because POR is low, all the core logic having async reset (created from POR) are put into reset state once the core supply ramps. POR must remain low through Power Stabilization Phase.
- Filtered versions of 1.8 V can ramp simultaneously with DVDD18.
- RESETSTAT is driven low once the DVDD18 supply is available.
- All input and bidirectional pins must not be driven or pulled high until DVDD18 is present. Driving an input or bidirectional pin before DVDD18 could cause damage to the device.
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2a |
- RESET may be driven high anytime after DVDD18 is at a valid level.
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2b |
- CVDD (core AVS) ramps up.
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3a |
- CVDD1 (core constant) ramps at the same time or following CVDD. Although ramping CVDD1 and CVDD simultaneously is permitted the voltage for CVDD1 must never exceed CVDD until after CVDD has reached a valid voltage.
- The purpose of ramping up the core supplies close to each other is to reduce crowbar current. CVDD1 should trail CVDD as this will ensure that the WLs in the memories are turned off and there is no current through the memory bit cells. If, however, CVDD1 (core constant) ramps up before CVDD (core AVS), then the worst case current could be on the order of twice the specified draw of CVDD1.
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3b |
- Once CVDD is valid, the clock drivers should be enabled. Although the clock inputs are not necessary at this time, they should either be driven with a valid clock or held in a static state with one leg high and one leg low.
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3c |
- The DDRCLK and SYSCLK1 may begin to toggle anytime between when CVDD is at a valid level and the setup time before POR goes high specified by t6.
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4 |
- DVDD15 (1.5 V) supply is ramped up following CVDD1.
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5 |
- POR must continue to remain low for at least 100 µs after power has stabilized.
End Power Stabilization Phase |
6 |
Begin Device Initialization
- Device initialization requires 500 SYSCLK1 periods after the Power Stabilization Phase. The maximum clock period is 33.33 nsec so a delay of an additional 16 µs is required before a rising edge of POR. The clock must be active during the entire 16 µs.
- POR must remain low.
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7 |
- RESETFULL is held low for at least 24 transitions of the SYSCLK1 after POR has stabilized at a high level.
- The rising edge of the RESETFULL will remove the reset to the efuse farm allowing the scan to begin.
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8 |
- Once device initialization and the efuse farm scan are complete, the RESETSTAT signal is driven high. This delay will be 10000 to 50000 clock cycles.
End Device Initialization Phase |
9 |
- GPIO configuration bits must be valid for at least 12 transitions of the SYSCLK1 before the rising edge of RESETFULL
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10 |
- GPIO configuration bits must be held valid for at least 12 transitions of the SYSCLK1 after the rising edge of RESETFULL
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