which pin is the BOOTDEVICESIZE input pin of AM3715?

Colman Lai said:

I found the NAND bus with is set to x16 by hardware. From the AM3715 Technical Reference Manual, it is set according to BOOTDEVICESIZE input pin. Which pin is the BOOTDEVICESIZE input pin?

There is not a specific BOOTDEVICESIZE pin.  Unfortunately the Technical Reference Manual implies there is a pin in Section 10.1.3.3.2, but actually this is at the GPMC module boundary inside the device.  Section 10.1.3.3.2 indicates the value of the BOOTDEVICESIZE is fixed at 0x1 at device reset, which implies a 16-bit data size for the external memory on the GPMC.  This is not changed.

Colman Lai said:

And also, which pin is the BOOTWAITSELECT input pin? I cannot find them in AM3715 datasheet and the Technical Reference Manual.

Section 26 of the Technical Reference Manual indicates which sys_boot[] pin options enable the wait monitoring.  With each boot mode option, there is an indication if wait monitoring is enabled and which wait input pin is used.  It turns out that only gpmc_wait0 is ever used.

Re-reading Section 26 of the Technical Reference Manual, in Section 26.4.7.4 discusses that 8-bit NAND is supported as the GPMC initially operates in 8-bit mode.