
68
6437E–ATARM–23-Apr-13
SAM9M11
Read commands: Read a byte (o), a halfword (h)oraword(w) from the target.
– Address: Address in hexadecimal
– Output: The byte, halfword or word read in hexadecimal following by ‘>’
Send a file (S): Send a file to a specified address
– Address: Address in hexadecimal
– Output: ‘>’.
Note:
There is a time-out on this command which is reached when the prompt ‘>’ appears before the
end of the command execution.
Receive a file (R): Receive data into a file from a specified address
– Address: Address in hexadecimal
– NbOfBytes: Number of bytes in hexadecimal to receive
– Output: ‘>’
Go (G): Jump to a specified address and execute the code
– Address: Address to jump in hexadecimal
– Output: ‘>’once returned from the program execution. If the executed program does
not handle the link register at its entry and does not return, the prompt will not be
displayed.
Get Version (V): Return the Boot Program version
– Output: version, date and time of ROM code followed by the prompt: ‘>’.
11.5.2
DBGU Serial Port
Communication is performed through the DBGU serial port initialized to 115200 Baud, 8 bits of
data, no parity, 1 stop bit.
11.5.2.1
Supported External Crystal/External Clocks
The SAM-BA Monitor supports a frequency of 12 MHz to allow DBGU communication for both
external crystal and external clock.
11.5.2.2
Xmodem Protocol
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 in order 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:
– <SOH> = 01 hex
– <blk #> = binary number, starts at 01, increments by 1, and wraps 0FFH to 00H (not
to 01)
– <255-blk #> = 1’s complement of the blk#.
– <checksum> = 2 bytes CRC16