The "main chip" in the HD/HDR-Fox T2 is the Broadcom BCM7405 System on a Chip (SoC).
The chip package is a 34 x 34 ball grid array (BGA) with each 'ball' only 1mm in diameter.
Only 976 positions are used, with a segregated square of balls in the middle containing power and ground for the chip and separate subsystems (USB, Ethernet, HDMI, Audio, Video DAC, clocks, RF/UHF, SATA).
Then the four sides of the outer balls are separated into one side for the memory bus connections, one side for USB/Ethernet/HDMI/Audio/RF/UHF/clocks/SATA/EJTAG, one side predominantly GPIO, and one side to PCI/EBI-VRAM/GPIO.