AT91RM9200-CI-002 Atmel, AT91RM9200-CI-002 Datasheet - Page 92

• Manufacturer Part Number: AT91RM9200-CI-002
• Description: IC ARM9 MCU 256 BGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91RM9200-CI-002

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 180MHz
• Connectivity: EBI/EMI, Ethernet, I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: POR
• Number Of I /o: 122
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: ROM
• Ram Size: 48K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 256-BGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

13.4
13.4.1
13.4.1.1
13.4.1.2
92
Boot Uploader
AT91RM9200
External Communication Channels
DBGU Serial Port
Xmodem Protocol
If no valid boot device has been found during the Bootloader sequence, initialization of serial
communication devices (DBGU and USB device ports) is performed.
The boot Uploader performs the DFU and Xmodem protocols to upload the application into inter-
nal SRAM at address 0x0020_0000.
The Boot Program uses a piece of internal SRAM for variables and stacks. To prevent any
upload error, the size of the application to upload must be less than the SRAM size minus 3K
bytes.
After the download, the peripheral registers are reset, the interrupts are disabled and the remap
is performed. After the remap, the internal SRAM is at address 0x0000_0000 and the internal
ROM at address 0x0010_0000. The instruction setting the PC to 0 is the one just after the remap
command. This instruction is fetched in the pipe before doing the remap and executed just after.
This fetch cycle executes the downloaded image.
The upload is performed through the DBGU serial port initialized to 115200 Baud, 8, n, 1.
The DBGU sends the character ‘C’ (0x43) to start an Xmodem protocol. 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 (Refer to the microcontroller
datasheet to determine SRAM size embedded in the microcontroller). In all cases, the size of the
binary file must be lower than 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
– Initialization of the DBGU serial port (115200 bauds, 8, N, 1) and Xmodem protocol
– Initialization of the USB Device Port and DFU protocol start
– Download of the application
– <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
start
to 01)
shows a transmission using this protocol.
1768I–ATARM–09-Jul-09