MIKROE-11 mikroElektronika, MIKROE-11 Datasheet - Page 33

• Manufacturer Part Number: MIKROE-11
• Description: Development Boards & Kits - AVR BIGAVR2 DEVELOPMENT SYSTEM
• Manufacturer: mikroElektronika

Specifications of MIKROE-11

• Rohs: yes
• Product: Development Kits
• Tool Is For Evaluation Of: ATMEGA128
• Core: AVR8
• Interface Type: IDC10, JTAG, RS-232, USB
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 bit
• For Use With: ATmega, AT90

MMC/SD (MULTIMEDIA CARD)
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MMC card is used as a storage media for a portable devices from which it can be easily
removed to enable data transfer to a PC. For example, a digital camera uses MMC card for
storing image files. Data can be easily transferred from MMC card to a PC using MMC read-
er. Modern computers, laptops and desktops usually have card readers with SD slots for read-
ing MMC cards.
Microcontroller on the BIGAVR2 development board communicates with MMC card via SPI
communication.
In order to enable MMC card, it is necessary to select and turn on switches 5, 6, 7, 8 of the switch
group SW2. The BIGAVR2 power supply voltage is 5V DC, whereas the MMC card power sup-
ply voltage is 3.3V DC. Because of that, there is an on-board voltage regulator MC33269DT-3.3.
For the same reason voltage level on data lines connecting the microcontroller to MMC card must
be limited to 3.3V. It is done by means of resistor voltage dividers as shown in Figure 44.
Figure 44
MMC/SD circuit diagram