EP9312-CBZ looking for tools and details.

Thread Starter


Joined Feb 4, 2023
EP9312-CBZ is an Arm chip from Cirrus Logic, now obsolete, found in many things, including a fostex MR-8HD multitrack recording device.

the fostex has a jumper with pins labelled RX, TX, reset and boot, and RX and TX are definitely connected to the CPU.

so far, without enough tools to do a proper investigation, i have been unable to read anything from these pins.

there is a lot of useful hardware in this machine, that i would like to repurpose.

i have not been able to find any record of anyone else trying to reverse engineer the fostex, am i missing anything?

does anyone know if there is anything available in terms of a development kit, cross compiler, firmware image builder?

or any better documentation than the datasheets?

i found this:


and the data sheet is here:


but beyond here, i'm stuck.