Artesyn SCP-P4040-4G-ENP2 Installation and Use (August 2014) - Manual (Page 32)

Functional Description
SCP-P4040-4G-ENP2 Installation and Use (6806800P60B) 32
4.5 Local Bus
The local bus is connected to a 2 Gb or 256 MB NOR Flash and a 08 G bits or 1 G Bytes NAND
flash. The NOR flash is used to store the RCW data, U-boot, and Linux kernel. By default, the
NAND flash is used to store the file system. There are a totally four chip-selectsignals included
in the local bus from CS0 to CS3. Among the CS0 to CS3, only CS0 is enabled during power on
reset. So, the chip-select-signal (CS) of the device connected to local bus from which the
system boots must be connected to CS0.
Local bus with 16 bits data bus (DQ0~DQ15) are directly routed to COM Express connectors.
A “low” state is required to enable local bus output and a “high” state or '1' is required to
disable.
The following figure illustrates the distribution of local bus on P4040:
Figure 4-2 Distribution of local bus on P4040