File Based ASIC Initialization Refinement (16-Sep-2009)

File Based ASIC Initialization Refinement

File-based ASIC Initialization

This publication describes a method that allows for an ASIC and corresponding initialization firmware manufacturer to develop said firmware in a way such that OEM vendors can independently customize the reset state of said ASIC.

Problem Domain

Most mass-produced ASICs have their reset states hardwired in the logic. Asserting a reset signal and/or applying operation power to the chip will drive the logic into these reset states. Changing any reset state can only be achieved by a modification of the chip design and production of new silicon.

If the behavior of the ASIC needs to be influenced depending on the external connections, the hardware design usually leaves some control elements to be programmed to match the environment. If this environment is fixed these programmed value can be configured by e.g. external pull-up/-down resistors or (if more extensive) may be stored in some kind of Read-Only Memory. If the number of control elements exceeds the capabilities of pure hardware solutions, some kind of initialization firmware (BIOS) is required.

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Figure 1: Firmware programs control elements within ASICs.

Problem Statement

Assuming that this ASIC + initialization firmware is sold to OEM and this OEM wants to customize the default initialization, the OEM has to ask the vendor to create a OEM specific version of the initialization firmware. The OEM and the vendor need to interact until the customization process is complete. Each iteration requires a new firmware build.

Description

Define documented jump-in points in the default initialization firmware, called hooks. If a chip firmware customization file exists, the initialization firmware will pause the default sequence at these hooks and read the custom...