User Manual

Apollo3 Blue Datasheet
DS-A3-0p9p1 Page 157 of 909 2019 Ambiq Micro, Inc.
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3.9.3 Flash Cache
3.9.3.1 Functional Overview
Figure 6. Block Diagram for Apollo3 Blue MCU with Flash Cache
Apollo3 Blue MCU incorporates a Flash cache to the ICode and DCode path from the microcontroller. This
controller is intended to provide single cycle read access to Flash and reduce overall accesses to the Flash
to reduce power. The controller is a unified ICode and DCode cache controller. The cache fill path is
arbitrated between cache misses as well as the other Flash read agents (Info, Reg, BIST). Caching is
supported for the entire 1MB internal Flash and the 64MB external Flash aperture (via MSPI).
The cache is configurable 2-way set associative or direct mapped, 512 or 256 entry and 128b linesize.