AT91SAM7X256B-AU Atmel, AT91SAM7X256B-AU Datasheet - Page 138

• Manufacturer Part Number: AT91SAM7X256B-AU
• Description: IC MCU 256KB FLASH 100LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7X256B-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: CAN, Ethernet, I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 62
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 64K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LQFP
• Package: 100LQFP
• Device Core: ARM7TDMI
• Family Name: 91S
• Maximum Speed: 55 MHz
• Operating Supply Voltage: 1.8|3.3 V
• Data Bus Width: 32 Bit
• Number Of Programmable I/os: 62
• Interface Type: CAN/Ethernet/SPI/I2S/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Number Of Timers: 3
• Controller Family/series: AT91SAM7xxxxx
• No. Of I/o's: 62
• Ram Memory Size: 64KB
• Cpu Speed: 55MHz
• No. Of Timers: 1
• Rohs Compliant: Yes
• Cpu Family: 91S
• Device Core Size: 32b
• Frequency (max): 55MHz
• Total Internal Ram Size: 64KB
• # I/os (max): 62
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 1.8/3.3V
• Operating Supply Voltage (max): 1.95/3.6V
• Operating Supply Voltage (min): 1.65/3V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 100
• Package Type: LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Compliant

21.4.2
21.4.3
138
AT91SAM7X512/256/128 Preliminary
Xmodem Protocol
USB Device Port
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 21-3
Figure 21-3. Xmodem Transfer Example
A 48 MHz USB clock is necessary to use the USB Device port. It has been programmed earlier
in the device initialization procedure with PLLB configuration.
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
www.usb.org, describes a way to implement devices such as ISDN modems and virtual COM
ports.
The Vendor ID is Atmel’s vendor ID 0x03EB. The product ID is 0x6124. These references are
used by the host operating system to mount the correct driver. On Windows systems, the INF
files contain the correspondence between vendor ID and product ID.
– <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
to 01)
shows a transmission using this protocol.
®
, from Windows 98SE to Windows XP
Host
SOH 02 FD Data[128] CRC CRC
SOH 01 FE Data[128] CRC CRC
SOH 03 FC Data[100] CRC CRC
ACK
EOT
ACK
ACK
ACK
C
®
. The CDC document, available at
Device
6120H–ATARM–17-Feb-09