Datasheet

SAM9G45 [DATASHEET]
Atmel-6438O-ATARM-SAM9G45-Datasheet_08-Dec-15
788
optional concept of suspend/resume (Refer to the SDIO Specification for more details). To send a suspend or a
resume command, the host must set the SDIO Special Command field (IOSPCMD) in the HSMCI Command
Register.
35.9.2 SDIO Interrupts
Each function within an SDIO or Combo card may implement interrupts (Refer to the SDIO Specification for more
details). In order to allow the SDIO card to interrupt the host, an interrupt function is added to a pin on the DAT[1]
line to signal the card’s interrupt to the host. An SDIO interrupt on each slot can be enabled through the HSMCI
Interrupt Enable Register. The SDIO interrupt is sampled regardless of the currently selected slot.
35.10 CE-ATA Operation
CE-ATA maps the streamlined ATA command set onto the MMC interface. The ATA task file is mapped onto MMC
register space.
CE-ATA utilizes five MMC commands:
 GO_IDLE_STATE (CMD0): used for hard reset.
 STOP_TRANSMISSION (CMD12): causes the ATA command currently executing to be aborted.
 FAST_IO (CMD39): Used for single register access to the ATA taskfile registers, 8 bit access only.
 RW_MULTIPLE_REGISTERS (CMD60): used to issue an ATA command or to access the control/status
registers.
 RW_MULTIPLE_BLOCK (CMD61): used to transfer data for an ATA command.
CE-ATA utilizes the same MMC command sequences for initialization as traditional MMC devices.
35.10.1 Executing an ATA Polling Command
1. Issue READ_DMA_EXT with RW_MULTIPLE_REGISTER (CMD60) for 8kB of DATA.
2. Read the ATA status register until DRQ is set.
3. Issue RW_MULTIPLE_BLOCK (CMD61) to transfer DATA.
4. Read the ATA status register until DRQ && BSY are set to 0.
35.10.2 Executing an ATA Interrupt Command
1. Issue READ_DMA_EXT with RW_MULTIPLE_REGISTER (CMD60) for 8kB of DATA with nIEN field set to
zero to enable the command completion signal in the device.
2. Issue RW_MULTIPLE_BLOCK (CMD61) to transfer DATA.
3. Wait for Completion Signal Received Interrupt.
35.10.3 Aborting an ATA Command
If the host needs to abort an ATA command prior to the completion signal it must send a special command to avoid
potential collision on the command line. The SPCMD field of the HSMCI_CMDR must be set to 3 to issue the CE-
ATA completion Signal Disable Command.
35.10.4 CE-ATA Error Recovery
Several methods of ATA command failure may occur, including:
 No response to an MMC command, such as RW_MULTIPLE_REGISTER (CMD60).
 CRC is invalid for an MMC command or response.
 CRC16 is invalid for an MMC data packet.
 ATA Status register reflects an error by setting the ERR bit to one.
 The command completion signal does not arrive within a host specified time out period.