at91sam9260-cj ATMEL Corporation, at91sam9260-cj Datasheet - Page 85

• Manufacturer Part Number: at91sam9260-cj
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

13.6.1
13.6.2
6221G–ATARM–31-Jan-08
DBGU Serial Port
Xmodem Protocol
Note:
Communication is performed through the DBGU serial port initialized to 115200 Baud, 8, n, 1.
The Send and Receive File commands use the Xmodem protocol to communicate. Any terminal
performing this protocol can be used to send the application file to the target. The size of the
binary file to send depends on the SRAM size embedded in the product. In all cases, the size of
the binary file must be lower than the SRAM size because the Xmodem protocol requires some
SRAM memory to work.
The Xmodem protocol supported is the 128-byte length block. This protocol uses a two-charac-
ter CRC-16 to guarantee detection of a maximum bit error.
Xmodem protocol with CRC is accurate provided both sender and receiver report successful
transmission. Each block of the transfer looks like:
<SOH><blk #><255-blk #><--128 data bytes--><checksum> in which:
Figure 13-9
• Read commands: Read a byte (o), a halfword (h) or a word (w) from the target.
• Send a file (S): Send a file to a specified address
• Receive a file (R): Receive data into a file from a specified address
• Go (G): Jump to a specified address and execute the code
• Get Version (V): Return the SAM-BA boot version
– Address: Address in hexadecimal
– Output: The byte, halfword or word read in hexadecimal following by ‘>’
– Address: Address in hexadecimal
– Output: ‘>’.
– Address: Address in hexadecimal
–
– Output: ‘>’
– Address: Address to jump in hexadecimal
– Output: ‘>’
– Output: ‘>’
– <SOH> = 01 hex
– <blk #> = binary number, starts at 01, increments by 1, and wraps 0FFH to 00H (not
– <255-blk #> = 1’s complement of the blk#.
– <checksum> = 2 bytes CRC16
NbOfBytes
to 01)
There is a time-out on this command which is reached when the prompt ‘>’ appears before the
end of the command execution.
shows a transmission using this protocol.
: Number of bytes in hexadecimal to receive
AT91SAM9260
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