AT91SAM7SE256B-CUR Atmel, AT91SAM7SE256B-CUR Datasheet - Page 232

• Manufacturer Part Number: AT91SAM7SE256B-CUR
• Description: IC ARM7 MCU FLASH 256K 128-LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7SE256B-CUR

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: EBI/EMI, I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 88
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K 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: *
• Processor Series: SAM7SE256
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 32 KB
• Interface Type: SPI, USB
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 88
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Operating Temperature Range: - 40 C to + 85 C
• Processor To Be Evaluated: AT91SAM7SE256B
• Supply Current (max): 60 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

25.4.2
25.4.3
232
SAM7SE512/256/32 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 25-3
Figure 25-3. 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
6222F–ATARM–10-Jan-11