M I K R O E L E K T R O N I K A S O F T W A R E A N D H A R D W A R E S O L U T I O N S F O R T H E E M B E D D E D W O R L D
dsPICPRO
USB
3
dsPICPRO3 User
’
s Manual
MikroElektronika
Development tools
2
28
8
page
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IIAA
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In order to enable MMC card you have to turn on switches 4, 5 and 6 on SW4 and switch
6 on SW2. By doing that, microcontroller SPI comunnication lines (SDI, SDO and SCK)
and Chip Select are connected to MMC. Working voltage of dsPICPRO3 is 5V DC, while
working voltage of MMC card is 3.3V DC. Because of that, there is on-board voltage reg-
ulator with MMC card (MC33269DT-3.3). Data lines from microcontroller to MMC card
must be also adjusted to 3.3V. It is done by resister voltage dividers as shown on Fig.35.
MMC card is used as a storage media for portable devices, in the form that can be easily
removed for access by PC. For example, digital camera uses MMC card to store image
files.With MMC reader (a small box connected to USB or some other serial connection)
user can easily transfer data from MMC card to a computer. Microcontroller on dsPICPRO3
communicates with Multi Media Card via SPI communication.
Figure 34.
on-board MMC slot
Modern comput-
ers, both laptops
and desktops,
usually have SD
slots which can
read MMC cards.
MMC/SD (MULTIMEDIA CARD)
MMC/SD
MASS STORAGE
MMC/SD
MASS STORAGE
SUPPORTED
SUPPORTED
256MB
