To Next Page

To Previous Page

Boot Loader

DFU_CMD_READ This command is used to set the address range of the content to be returned

on subsequent DFU_UPLOAD requests from the host.

The start address is provided in terms of 1024-byte ﬂash blocks. To convert a

byte address to a block address, divide by 1024. The start address must always

be on a 1024-byte boundary.

To read back a the contents of a region of ﬂash, the host should send a

DFU_DNLOAD request with command DFU_CMD_READ, start address set to the

1KB block start address and length set to the number of bytes to read. The

host should then send one or more DFU_UPLOAD requests to receive the cur-

rent ﬂash contents from the conﬁgured addresses. Data returned includes an

8-byte DFU_CMD_PROG preﬁx structure unless the preﬁx has been disabled by

sending a DFU_CMD_BIN command with the bBinary parameter set to 1. The

host should, therefore, be prepared to read 8 bytes more than the length spec-

iﬁed in the READ command if the preﬁx is enabled.

By default, the 8-byte preﬁx is enabled for all upload operations. This preﬁx

is required by the DFU class speciﬁcation which states that uploaded images

must be formatted to allow them to be directly downloaded back to the device

at a later time.

The format of the command is as follows:

uint8_t pui8Data[8];

pui8Data[0] = DFU_CMD_READ (0x02)

pui8Data[1] = Reserved - set to 0x00

pui8Data[2] = Start Block Number [7:0];

pui8Data[3] = Start Block Number [15:8];

pui8Data[4] = Image Size [7:0];

pui8Data[5] = Image Size [15:8];

pui8Data[6] = Image Size [23:16];

pui8Data[7] = Image Size [31:24];

18 April 8, 2013

Texas Instruments Tiva TM4C123GH6PM User Manual

Questions and Answers: