Tom's computer pages

January 18, 2025

Antminer S9 board - Jumpers and boot modes

Unlike the EBAZ boards, these have handy jumpers readily available that allow you to select the boot mode. If you begin reading the TRM, be warned that the MIO pin order is not the same as the BM (boot mode) order shown here.

Near the SD card slot are four jumpers labeled JP1 to JP4.

To boot from onboard NAND flash (mode 4), set them:

JP4 (BM0-MIO5) ---*  0
JP3 (BM1-MIO3) ---*  0
JP2 (BM2-MIO4) *---  1
JP1 (BM3-MIO2) ---*  0

To boot from the SD card (mode 5), set them like so:

JP4 (BM0-MIO5) *---  1
JP3 (BM1-MIO3) ---*  0
JP2 (BM2-MIO4) *---  1
JP1 (BM3-MIO2) ---*  0

In general I mostly use the SD card boot, but sometimes move JP4 to boot from onboard NAND.
You can always ignore JP1.

To use the secret UART boot (mode 3), set them like so:

JP4 (BM0-MIO5) *---  1
JP3 (BM1-MIO3) *---  1
JP2 (BM2-MIO4) ---*  0
JP1 (BM3-MIO2) ---*  0

A full list of modes

; 0 = JTAG
; 1 = Quad-SPI
; 2 = NOR
; 3 = UART (secret)
; 4 = NAND
; 5 = SD card
; 6 = ??
; 7 = ??