Artesyn ATCA-F125 Installation and Use Guide (April 2014) - Manual (Page 73)

Functional Description
ATCA-F125 (6873M Artwork) Installation and Use (6806800J94J) 73
 BCM8747 microcode Flash programming - The same SPI controller in the FPGA is used as
with configuration Flash programming, but now AUX_SS is driven instead of CSO_B (which
is deasserted), allowing SPI Flash 3 to be programmed.
 BCM8747 microcode loading - The SPI port from the BCM8747 is routed to AUX_CS, CCLK,
MOSI and DIN pins in the FPGA to allow the microcode to be read from SPI Flash 3.
Figure 4-3 FPGA SPI ROM Configuration