NB2DSK01 - Serial SPI Flash Memory
The NB2DSK01 provides serial Flash memory in the form of two M25P80 8-Mbit devices (from STMicroelectronics). These devices support a serial data rate of 25MHz. The M25P80 is an SPI-compatible device, with both devices accessed through the NB2DSK01's SPI Controller, which itself resides within the Xilinx Spartan-3 NanoTalk Controller.
Figure 1. Serial Flash memory.
The function of the two devices (designated U20 and U21) can be summarized as follows:
- U20 – used as Embedded memory. This device is used to provide embedded memory functionality within an FPGA design, enabling you to load and store an embedded software file that will be used when the target design is running.
- U21 – used as either Embedded memory or Boot memory. This device can be used from within an FPGA design, as described above. It can also be used to store the programming file required for implementing a design within the daughter board FPGA. This gives you the ability to 'bootstrap' the FPGA device upon powering-up the NB2DSK01.
The SPI Flash memory devices can be erased and programmed from within Altium Designer, using the Instrument panel for the NanoTalk Controller.
Location on Board
The two M25P80 devices (U20 and U21) are located on the component side of the board, above the Xilinx Spartan-3 NanoTalk Controller device (U5). These devices, along with all other NB2DSK01 memories, the NanoTalk Controller and the configuration PROM, are covered by the TFT LCD panel.
Schematic Reference
The SPI Flash memory devices can be found on Sheet 40 (FLASHSPI_M25PX0.SchDoc, entitled Dual Serial Flash Memory) of the motherboard schematics.
Design Interface Component
Table 1 summarizes the available design interface component that can be placed from the FPGA NB2DSK01 Port-Plugin.IntLib, to access and use the SPI Flash memory devices.
| Component Symbol | Component Name | Description |
|---|---|---|
| SERIALFMEMORY | Place this component to access the signals relating to the SPI Flash memory device used to facilitate embedded memory. |
If your design involves communications with multiple SPI-based devices, you will need to place the generic SPI_BUS device. For more information, see Using Multiple SPI and I2C Devices in a Design.
Further Device Information
For more information on the M25P80 device, refer to the datasheet (m25p80.pdf) available at www.st.com.