PCB Design Guidelines (HSSI, EMIF, MIPI, True Differential, PDN) User Guide: Agilex™ 5 FPGAs and SoCs
4.1. Pin Distribution and Ball Pitches
For VPBGA packaging board design, you must first understand the different ball pitches for different IO functions at different location in the package, then follow the guidance to plan the signal routing accordingly.
The following Agilex™ 5 A5E065B example shows the pin distribution for different functions.
Generally, power pins are concentrated in the middle area of BGA, GPIO pins are located at the north and south sides, and transceiver pins are spread at the east and west sides. Most Agilex™ 5 devices adopt VPBGA package and have different pitches in different BGA functional areas. In the transceiver and power areas, the pitch is 0.75 mm on the x-axis and 0.77 mm on the y-axis. In the GPIO area, including EMIF, the pitch is 0.65 mm, while every two columns have a larger spacing of approximately 1.45 mm for easier fan out. The range of ball pitches of all Agilex™ 5 VPBGA devices is from 0.65 mm to 1.45 mm. For more details, refer to the specific device’s footprint.
Take note that 0.65 mm ball pitch exists on the outermost two rows or columns for GPIO as shown in the yellow boxes in Example of 0.65 mm Pitch for B32A Package figure. Altera recommends using microstrip routing for the GPIOs on the outermost two rows on the top layer to avoid PTH vias and simplify the inner layer routing.