Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD Scheda Tecnica

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SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13



Get Version (V): Return the SAM-BA boot version



Output: ‘>’

Communication is performed through the UART0 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. See, 

The Xmodem protocol supported is the 128-byte length block. This protocol uses a two-character 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 

The device uses the USB communication device class (CDC) drivers to take advantage of the installed PC RS-232
software to talk over the USB. The CDC class is implemented in all releases of Windows

®

, from Windows 98SE to

Windows XP. The CDC document, available at www.usb.org, describes a way to implement devices such as ISDN
modems and virtual COM ports. 

Host

Device

SOH 01 FE Data[128] CRC CRC

C

ACK

SOH 02 FD Data[128] CRC CRC

ACK

SOH 03 FC Data[100] CRC CRC

ACK

EOT

ACK