AT91SAM9R64 Datasheet, PDF (82/911 Pages) ATMEL Corporation – Thumb Microcontrollers

AT91SAM9R64/RL64 Preliminary
Table 14-3. Handled Standard Requests (Continued)
Request
Definition
GET_STATUS
Returns status for the specified recipient.
SET_FEATURE
Used to set or enable a specific feature.
CLEAR_FEATURE
Used to clear or disable a specific feature.
The device also handles some class requests defined in the CDC class.
Table 14-4. Handled Class Requests
Request
Definition
SET_LINE_CODING
Configures DTE rate, stop bits, parity and number of
character bits.
GET_LINE_CODING
Requests current DTE rate, stop bits, parity and number
of character bits.
SET_CONTROL_LINE_STATE
RS-232 signal used to tell the DCE device the DTE
device is now present.
Unhandled requests are STALLed.
14.7.3.2
Communication Endpoints
There are two communication endpoints and endpoint 0 is used for the enumeration process.
Endpoint 1 is a 512-byte Bulk OUT endpoint and endpoint 2 is a 512-byte Bulk IN endpoint.
SAM-BA Boot commands are sent by the host through the endpoint 1. If required, the message
is split by the host into several data payloads by the host driver.
If the command requires a response, the host can send IN transactions to pick up the response.
14.8
Hardware and Software Constraints
• A 12 MHz Crystal is mandatory in order to generate correctly 480 MHz clock necessary for
the USB High Speed Device and to generate the 48 MHz System clock.
• No Bypass Mode.
• The SD Card, NAND Flash and DataFlash downloaded code size must be inferior to 56 K
bytes.
• The code is always downloaded from the DataFlash or NAND Flash device address
0x0000_0000 to the address 0x0000_0000 of the internal SRAM (after remap).
• The downloaded code must be position-independent or linked at address 0x0000_0000.
• The DataFlash must be connected to NPCS0 of the SPI.
The MCI, the SPI and NAND Flash drivers use several PIOs in alternate functions to communi-
cate with devices. Care must be taken when these PIOs are used by the application. The
devices connected could be unintentionally driven at boot time, and electrical conflicts between
peripherals output pins and the connected devices may appear.
To assure correct functionality, it is recommended to plug in critical devices to other pins.
Table 14-5 contains a list of pins that are driven during the boot program execution. These pins
are driven during the boot sequence for a period of less than 1 second if no correct boot program
is found.
82
6289A–ATARM–15-Jan-08