The NEXYS3 is used instead of traditional NOR FLASH devices. PCM is a newer memory that combines DRAM, FLASH, and EEPROM many memory characteristics. The main feature is non-volatile, bit reading function, fast read and write speed, scratch-resistant writing and data storage time. These features of PCM make it more flexible design, significantly improve the performance of the system under special needs of certain systems.
Nexys3 uses Micron's parallel PCM (128MB NP8P128A13T1760E) and serial PCM (128MB NP5Q128A13ESFC0E) to use as the system's parallel Flash and serial Flash. Compared to traditional NOR FLASH, PCM has faster read and write and erase speeds, and can perform bit unit operations. Although the PCM does not require erase operations, Micron simulates almost all Flash functions in order to make the design better compatible with traditional Flash. Therefore, PCM and NOR FLASH are almost completely compatible, so that the design can be upgraded to PCM, and hardware and hardware do not need to make great changes. Nexys3 can also be used as an evaluation board for a PCM.
Open the previously established system, add a flash, XPS Multi-Channel External Memory Controller IP.
Data bus still 16
Time parameters still have to refer to the manual of parallel PCM.
Connect with MEM_BUS_MUX. You can compare with the RAM signal connection, the chip select, the output enable, the write signal is basically the same. Parallel PCM has no data 8-bit and 16-bit selection signals, so only 16 reads. MEM_RPN is equivalent to the RST signal in Flash.
After the signal is connected, the bus interface column is also selected by MB_PLB, and the address assigns a 16MB range. Then start compiling the stream file hardwar->generate BitStream.
Also import hardware into EDK. First, it is generated into a new BSP driver support package. Then you can test the program. The procedure for NOR FLASH should be able to test PCM directly.
Try the manufacturer and chip ID number read by the chip, add the following code.
Select Xilinx Tools->Program FPGA after compile, then the .elff file is generated, right-click. Click .Elf file Select Run as->launch on hardware. Serial port can be monitored
You can see that 0x89 is Micron's vendor number, 0x881e is the ID number of this chip.
Under the EDK software, select Xilinx Tools->program Flash, which will pop up the window can be added directly to the PCM.
There is a customized serial PCM control IP in the BSB support package of Nexys3, which can support Quad mode with the SPI interface.
Adding this IP is simple, set a good address, and the signal is also connected to MEM_BUS_MUX.
summary:
Add parallel Flash to the system, the settings of the RAM, pay attention to the signal and time parameters. PCM is fully compatible with NOR Flash, which can be very convenient. Nexys3 can be used as a PCM's evaluation board for development, and some of the PCM can be used as a good supplement to the system design, improve the performance of the system.
Reference link:
http://www.xilinx.com/support/documentation/spartan-6.htm
http://www.digilentinc.com/products/detail.cfm?navpath=2,400,897&prod=Nexys3
Http://www.microchip.com/wwwproducts/devices.aspx?ddoccname=en531074
Http://www.eefocus.com/Article/09-11/14308007111132pytd.html
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