There are several different embedded controller chips that have been
used over the thinkpad range.  This file lists the ones that we have
seen and is a place for recording information about them.

It is not intended to be an exhaustive list, as that would require
schematics, physical inspection or reverse engineering the EC firmware
for a lot of different models.

ThinkPad T4x/p and R5x/p:
-------------------------
    Renesas H8S/2161BV
    (source: http://forum.thinkpads.com/viewtopic.php?t=20958)

ThinkPad x220:
--------------
    Renesas H8S R4F2113NFT-1-GP
    Looks very similar to the 2161BV

    (source: physical inspection, reverse engineering the EC firmware
    and the schematics - http://plan9.stanleylieber.com/hardware/thinkpad/x220/x220.schematics.pdf)

ThinkPad xx30 series:
---------------------
    SMSC/Microchip MEC1619L-AJZP-GP

    This is a 32-bit ARC core CPU, with most of the firmware written using
    the ARCompact variant of the instruction set

    MEC product family specs:
        http://pdf.datasheetarchive.com/indexerfiles/Datasheets-EC3/DSAQ00359444.pdf
    Microchip product page:
        https://www.microchip.com/wwwproducts/en/MEC1619
        (note that microchip does not have a real datasheet available but there is one for the similar MEC1618:
        http://ww1.microchip.com/downloads/en/DeviceDoc/00002339A.pdf)

    (source: physical inspection, reverse engineering the EC firmware
    and the schematics - http://plan9.stanleylieber.com/hardware/thinkpad/x230/x230.schematics.pdf)

    This chip has a JTAG programming port, so it is possible to read and
    write the firmware with an external programmer, which might help in
    the case of a bricked system.
    (see discussion: http://notebook1.ru/forma1/viewtopic.php?f=70&t=109179)
    The procedure for doing this is documented here: https://github.com/taglour/x230-ec-jtag

ThinkPad l420:
--------------
    IT8511TE

    This is a 8051 core CPU.

    (source: schematics - http://www.informaticanapoli.it/download/SCHEMIELETTRICI/IBM-LENOVO/Lenovo%20laptop%20motherboard%20schematic%20diagram.pdf)

Thinkpad l430/l530:
-------------------
    Nuvoton NPCE885G

    This is a CR16C core CPU.

ThinkPad e330:
--------------
    Nuvoton NPCE885G

    (source: EC firmware similarity to the l430)

Thinkpad x250:
--------------
    An ARCompact instruction set CPU, so probably a MEC1619

    (source: reverse engineering the EC firmware)

Thinkpad x260:
--------------
    An ARCompact instruction set CPU, so probably a MEC1619

    (source: reverse engineering the EC firmware)