MEC1404 Datasheet, PDF (65/572 Pages) Microchip Technology – Keyboard and Embedded Controller Products for Notebook PC

MEC140X/1X
2.12 Strapping Options
2.12.1 BOOT SOURCE SELECT STRAPS
The Crisis Recovery Strap option (CR_STRAP) is implemented on GPIO102/KSO09[CR_STRAP].
• If this pin is connected to ground the Boot ROM will load the SPI Flash image from the SPI Flash located on the
Private SPI Interface (PVT_xxxx).
• If this pin is pulled high, which is the normal operation for the Key Scan Interface, the Boot ROM will load the SPI
Flash image from the Shared Flash Interface (SHD_xxxx) or the eSPI Flash channel as selected by the Boot
Source Select Strap (BSS_STRAP) on the GPIO123/SHD_CS# pin.
CR_STRAP
0
1
BSS_STRAP
X
0
1
Source
Use 3.3V Private SPI
Use eSPI Flash Channel
Use 3.3V Shared SPI
Note:
If the eSPI Flash Channel is used for booting, the GPIO123/SHD_CS# pin must be used as RSMRST#. This
pin will be driven high by the boot ROM code in order to activate the eSPI flash channel.
If the SHD_SPI port is used for booting, then any unused GPIO may be used for RSMRST#.
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DS00001956D-page 65