LAN969x Strapping Modes

All EVBs have a 4-way DIP switch which is used to control the boot mode. The location of the DIP switch varies, but it always has a silk print saying "Boot mode".

The boot mode is only sampled at boot time, which means that when changing the boot mode, the board needs to be reset.

The following table documents the relevant boot modes used by VelocityDRIVE-SP:

Strap Value DIP Setting LAN969x (A0)

0001 (0x1)
dip lan969x 1

Default development boot mode for VelocityDRIVE-SP
Booting from NOR-Flash BootROM traces activated on FlexCOM-0 in UART mode 115200 1N8.

0100 (0x4)
dip lan969x 4

Default boot mode for VelocityDRIVE-SP
Booting from NOR-Flash BootROM traces disabled.
VelocityDRIVE uses FlexCOM-0 in UART mode 115200 1N8.

1010 (0xa)
dip lan969x 10

De-brick mode.
Booting into ROM monitor using UART.
FlexCOM-0 in UART mode 115200 1N8.

1011 (0xb)
dip lan969x 11

De-brick mode (high-speed UART).
Booting into ROM monitor using UART.
FlexCOM-0 in UART mode 921600 1N8.
VelocityDRIVE uses FlexCOM-0 in UART mode 115200 1N8 (to be changed).

1101 (0xd)
dip lan969x 13

Supported by VelocityDRIVE-SP
Booting from NOR-Flash BootROM traces disabled.
VelocityDRIVE uses FlexCOM-0 in UART mode 115200 1N8.

1. Strapping impact on NOR flash

The SoC have 3 different strapping settings which configures the device to boot from NOR Flash. The table below documents the per-strapping, per-boot-stage NOR flash speed and mode.

Strap Value BL1-NOR BL2-NOR VelocityDRIVE-SP-NOR

0001 (0x1)

25Mhz@1-1-1

100Mhz@1-4-4

100Mhz@1-4-4

0100 (0x4)

25Mhz@1-1-1

100Mhz@1-4-4

100Mhz@1-4-4

1101 (0xd)

100Mhz@1-4-4

100Mhz@1-4-4

100Mhz@1-4-4

In the table above the 3 digits after the @ symbol indicate the width (number of data-lines) for command, address and data. 1-1-1 is generally referred to as single SPI (only one data line used for command, address and data). 1-4-4 is generally referred to as QSPI-NOR, where only one data line is used to transfer the command, but address and data are transmitted using 4 data lines.

The LAN969x has only been tested using QSPI-NOR flashes from the SST26 family, and the implementation has been hard-coded to use this command set. Other devices may work if they are compatible, but the device does not support SFDP.

2. Additional Non-VelocityDRIVE-SP Strap Modes

The following modes are defined by the SoC, but are not relevant in a VelocityDRIVE-SP application.

Strap Value DIP Setting LAN969x (A0)

0000 (0x0)
dip lan969x 0

Not directly supported by VelocityDRIVE-SP
Booting from eMMC.
BootROM traces activated on FlexCOM-0 in UART mode 115200 1N8.
Can be used to boot into UBoot, which can start VelocityDRIVE-SP.
NOTE: Not all boards have eMMC mounted.

0010 (0x2)
dip lan969x 2

Not directly supported by VelocityDRIVE-SP
Booting from SD-Card.
BootROM traces activated on FlexCOM-0 in UART mode 115200 1N8.
Not supported with current EVBs, and not all SD-cards are supported.

0011 (0x3)
dip lan969x 3

Not directly supported by VelocityDRIVE-SP
Booting from eMMC.
BootROM traces disabled.
VelocityDRIVE uses FlexCOM-0 in UART mode 115200 1N8.
Can be used to boot into UBoot, which can start VelocityDRIVE-SP.
NOTE: Not all boards have eMMC mounted.

0101 (0x5)
dip lan969x 5

Not directly supported by VelocityDRIVE-SP
Booting from SD-Card.
BootROM traces disabled.
Not supported with current EVBs, and not all SD-cards are supported.

0110 (0x6)
dip lan969x 6

Not supported / reserved for future use.

0111 (0x7)
dip lan969x 7

Not supported / reserved for future use.

1000 (0x8)
dip lan969x 8

Not directly supported by VelocityDRIVE-SP yet
Booting from SPI-NOR 100Mhz mode 1-4-4
BootROM traces activated on FlexCOM-0 in UART mode 115200 1N8.
VelocityDRIVE uses FlexCOM-0 in UART mode 921600 1N8.

1001 (0x9)
dip lan969x 9

Not supported / reserved for future use.

1100 (0xc)
dip lan969x 12

Not supported / reserved for future use.

1110 (0xe)
dip lan969x 14

Not supported / reserved for future use.

1111 (0xf)
dip lan969x 15

Not supported by VelocityDRIVE-SP
CPU disabled, and chip is initialized in SPI-Device mode