This is the most critical part of the datasheet. If you ignore the Power-Up Sequencing table, your board will latch up.
The Aspeed AST2500 datasheet specifies three core voltages:
The Rule: According to Section 7.2 of the datasheet, 3.3V must ramp last. Aspeed Ast2500 Datasheet
Why this matters: If you apply 3.3V before 0.9V, internal ESD diodes will forward bias, sending current into the core illegally. The datasheet is explicit about a maximum ramp time of 100ms. Violating this is the #1 cause of "dead AST2500" on custom carrier boards.
[Host Server] <--PCIe/LPC--> [AST2500] <--I2C--> [Temp sensor, PSU]
<--GPIO--> [Fan control, Power button]
<--Ethernet--> [Remote admin LAN]
<--VGA--> [Front/rear VGA port]
Ball Map: The datasheet provides full ball assignment, including: This is the most critical part of the datasheet
Before finalizing a design based on the AST2500 datasheet, check Aspeed's Product Status.
Pin Compatibility: Critical. The datasheet reveals the AST2500 and AST2600 are NOT pin-to-pin compatible. The Rule: According to Section 7
The AST2500 requires multiple voltage rails, and the datasheet specifies tight tolerances:
Power Sequencing: The datasheet mandates that Vcore must rise after VDD_IO, with a maximum delay of 100ms. Failure to follow this can cause latch-up or improper boot.