Using the ATEVK525
ATEVK525 Mass Storage Board for AVR
2-7
7740B–AVR–03/08
2.1.3
Protection circuitry
The ATEVK525 includes an optional power supply protection circuit that prevents on-
board resources from being damaged.
Figure 2-3 .
Power protection circuit location
This supplement, if mounted, protects the storage devices from voltage above 3.5V. In
case of overvoltage detection, the power positive line of the extension board is not
connected to devices, and the LED “PWR_FAIL” is lit.
If the supplement is not mounted or needs to be disabled, the solder pad SP1 must be
soldered to connect power supply of the on-board resources (see photo above).
2.2
NAND Flash
2.2.1
Default device
The ATEVK525 comes with one NAND Flash chip soldered. At the time of writing, this
chip is the Micron MT29F2G08AACWP that features:
2 GBits (256 MBytes) organized as:
– 2048 blocks
– block size : 64 pages
– page size : 2112 bytes (2048 + 64 in spare zone)
Page program time of 300µs, Block erase time of 2ms
Copy-Back feature (enable cache transfers between blocks to speed up write
operation; no memory zone / address limitation)
The memory access is managed by the External Memory Interface hardware peripheral
of the AT90USBxxx microcontroller. Data and Address information share the same 8-bit
wide bus connected to the lowest bits of Memory Interface (A7-A0), while the Control
signals are connected to upper bits:
