The main functionality of the tool is to generate the Device Configuration Data (DCD) image using the format and constrains specified Boot ROM reference manual.
Upon reset, all peripheral registers in the system have their default values. However, these settings typically are not ideal for achieving optimal system performance. Moreover, there are some peripherals that must be configured before they can even be used. DCD is the configuration information contained in the DCD Image, that the Boot ROM interprets to configure various peripherals on the device. The Boot ROM determines the location of the DCD table by the pointer in the Image Vector Table.
The maximum size of the DCD image is 8192 bytes.
The DCD data is comprised of the following three type of commands :
The Write Data command is used to write a list of given 1-byte, 2-byte, or 4-byte values (or bitmasks) to a corresponding list of target addresses. The format of Write Data commands are a big-endian byte array.
The command's target width refers to it's value size (1, 2 or 4 bytes).
The address must be a multiple of the target width.
The command's action can be one of the following :
| Action | Interpretation |
| *address = val_mask | Write value |
| *address &= ~val_mask | Clear bitmask |
| *address |= val_mask | Set bitmask |
The Check Data command is used to test for a given 1, 2, or 4-byte bitmasks from a source address. The Check data command is a big endian byte array
The command's target width refers to it's value size (1, 2 or 4 bytes).
The address must be a multiple of the target width.
The command's action can be one of the following :
| Action | Interpretation |
| (*address & mask) == 0 | All bits in mask clear |
| (*address & mask) == mask | Bits in mask are set |
| (*address & mask) != mask | Bits in mask are clear |
| (*address & mask) != 0 | Any bit in mask set |
This command has no effect. The format of NOP Command is a big endian 4-byte array