AT32UC3A4256 Atmel Corporation, AT32UC3A4256 Datasheet - Page 819

• Manufacturer Part Number: AT32UC3A4256
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A4256

• Flash (kbytes): 256 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• Hardware Qtouch Acquisition: No
• Usb Transceiver: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 2
• Uart: 4
• Ssc: 1
• Sd / Emmc: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 128
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.0 to 3.6
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

30.6.2
32072G–11/2011
MultiMedia Card Operations
Figure 30-8. Mixing MultiMedia and SD Memory Cards with Two Slots
When the MCI is configured to operate with SD memory cards, the width of the data bus can be
selected in the SDCard /SDIO Bus Width field in the SDCR register (SDCR.SDCBUS).
tion “30.7.4” on page 840.
In the case of multimedia cards, only the data line 0 is used. The other data lines can be used as
independent GPIOs.
When more than one card (MMC or SD) is plugged to the device, it is strongly recommended to
connect each card’s clock to a dedicate MCI CLK pin of the device. Otherwise, Compliance to
specifications is not guaranteed.
After a power-on reset, the cards are initialized by a special message-based MultiMedia Card
bus protocol. Each message is represented by one of the following tokens:
Card addressing is implemented using a session address assigned during the initialization
phase by the bus controller to all currently connected cards. Their unique CID number identifies
individual cards.
• Command: a command is a token that starts an operation. A command is sent from the host
• Response: a response is a token which is sent from an addressed card or (synchronously)
• Data: data can be transferred from the card to the host or vice versa. Data is transferred via
either to a single card (addressed command) or to all connected cards (broadcast
command). a command is transferred serially on the CMD line.
from all connected cards to the host as an answer to a previously received command. A
response is transferred serially on the CMD line.
the data line.
DATA[11:8]
DATA[7:0]
CMD[0]
CMD[1]
CLK
CLK
for details.
910
1 2 3 4 5 6
11
MMC1
1213 8
SDCARD
7
910
1 2 3 4 5 6
11
MMC2
1213 8
7
910
1 2 3 4 5 6
11
MMC3
1213 8
7
See Sec-
819