The values used by the Get_Mode() function are shown in
.
Table 2-6. OTP Values for GetMode
Address
Name
Value
0x3D7BFB
OTP_KEY
GetMode will be entered if one of the two conditions is true:
Case 1: TRST == 0, GPIO34 == 1 and GPIO37 == 1
Case 2: TRST == 1, EMU_KEY == 0x55AA and EMU_BMODE == GET_BOOT
GetMode first checks the value of OTP_KEY:
if OTP_KEY == 0x005A, then check OTP_BMODE for the boot mode
else { Invalid key: Boot mode = FLASH_BOOT }
0x3D7BFE
OTP_BMODE
0x0001
Boot mode = SCI_BOOT
0x0004
Boot mode = SPI_BOOT
0x0005
Boot mode = I2C_BOOT
0x0006
Boot mode = OTP_BOOT
0x0007
Boot mode = CAN_BOOT
Other
Boot mode = FLASH_BOOT
The following boot modes are available through the emulation boot option. Some are also available as a
programmed get mode option.
•
Jump to M0 SARAM
This mode is only available in emulation boot. The boot ROM software configures the device for C28x
operation and branches directly to address 0X000000. This is the first address in the M0 memory block.
•
Jump to branch instruction in flash memory.
Jump to flash is the default behavior of the Get Mode boot option. Jump to flash is also available as an
emulation boot option.
In this mode, the boot ROM software configures the device for C28x operation and branches directly to
location 0x3F 7FF6. This location is just before the 128-bit code security module (CSM) password locations.
You are required to have previously programmed a branch instruction at location 0x3F 7FF6 that will redirect
code execution to either a custom boot-loader or the application code.
•
Jump to OTP Memory
Jump to OTP is available only as an option programmed into OTP_BMODE via the get mode function. With
the debug probe connected, jump to OTP can also be achieved by manually writing the OTP_BOOT value to
EMU_BMODE. The entry point location is 0x3D 7800.
•
SPI EEPROM or Flash boot mode (SPI-A)
Jump to SPI is available in stand-alone mode as a programmed Get Mode option. That is, to configure a
device for SPI boot in stand-alone mode, the OTP_KEY and OTP_BMODE locations must be programmed
for SPI_BOOT and the boot mode pins configured for the Get Mode boot option.
SCI boot is also available as an emulation boot option.
In this mode, the boot ROM will load code and data into on-chip memory from an external SPI EEPROM or
SPI flash via the SPI-A port.
•
I2C-A boot mode (I2C-A)
Jump to I2C is available in stand-alone mode as a programmed Get mode option. That is, to configure a
device for I2C boot in stand-alone mode, the OTP_KEY and OTP_BMODE locations must be programmed
for I2C_BOOT and the boot mode pins configured for the Get Mode boot option.
I2C boot is also available as an emulation boot option.
Boot ROM
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
TMS320x2806x Microcontrollers
209
Copyright © 2022 Texas Instruments Incorporated
Summary of Contents for TMS320 2806 Series
Page 2: ......