Micro Sd Card File System Read - Terasic DE0-CV User Manual

Table 5-2 Description of 7-segment Display and LED Indicators
Indicator Name
LEDR0
LEDR1
LEDR2
HEX0
HEX1
HEX2
HEX3
5 . 5
5 . 5
M i c r o
M i c r o
Many applications use a large external storage device, such as a SD Card or CF card to store data.
The DE0-CV board provides the hardware and software needed for Micro SD Card access. In this
demonstration we will show how to browse files stored in the root directory of an SD Card and how
to read the file contents of a specific file. The Micro SD Card is required to be formatted as FAT
File System in advance. Long file name is supported in this demonstration.
hardware system block diagram of this demonstration. The system requires a 50MHz clock
provided by the board. The PLL generates a 100MHz clock for the Nios II processor and other
controllers. Four PIO pins are connected to the Micro SD Card socket. SD 4-bit Mode is used to
access the Micro SD Card hardware.The SD 4-bit protocol and FAT File System function are all
implemented by Nios II software. The software is stored in the on-chip memory.
DE0-CV User Manual
Description
S D C a r d f i l e
S D C a r d f i l e
Figure 5-7 Block diagram of the Micro SD demonstration
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Left button press indicator
Right button press indicator
Middle button press indicator
Low byte of X displacement
High byte of X displacement
Low byte of Y displacement
High byte of Y displacement
s y s t e m r e a d
s y s t e m r e a d
Figure 5-7 shows the
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May 4, 2015