emPC-CX+
(
System Reference
Manual)
FPGA expansion subsystem
2 - 21
Rev. 1.2
©
Janz Tec AG
2.4
NVRAM
The emPC-CX+ implements an integrated mRAM memory. This device implements 128kx8 NVRAM.
The NVRAM is a fast SRAM style device, however there is no need for battery maintenance.
Address
Description
BAR5 + 0x080000..0x09FFFF
NVRAM area
Table 11: NVRAM address (128KByte NVRAM)
The NVRAM can be accessed by 8-, 16- and 32 bit operations (read and write).
If NVRAM is accessed by 32 bit operations, these are not atomic. In case of power down,
it might happen that only parts of the 32 bit value are stored in the nvSRAM. Also notice
that the PCI interface has buffers. Even if the write operation has been finished from
CPU point of view, it might not have been saved into the memory. To make sure data
has reached the memory, you need to read back the latest written content.
Summary of Contents for emPC-CX+
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