Memory

The DE2 board provides an 8-Mbyte SDRAM, 512-Kbyte SRAM, and 4-Mbyte (1-Mbyte on some boards) Flash memory. Figures 1, 2, and 3 show the schematics of the memory chips. The pin assignments for each device are listed in Table 1. The datasheets for the memory chips are provided in the references.

Figure 1. SDRAM schematic.

Figure 2. SRAM schematic.

Figure 3. Flash schematic.

Table 1. Signal assignments for the memory chips.

Signal NameDescription
DRAM_ADDR[11:0] SDRAM Address[11:0]
DRAM_DQ[15:0] SDRAM Data[15:0]
DRAM_BA_0 SDRAM Bank Address[0]
DRAM_BA_1 SDRAM Bank Address[1]
DRAM_LDQM SDRAM Low-byte Data Mask
DRAM_UDQM SDRAM High-byte Data Mask
DRAM_RAS_N SDRAM Row Address Strobe
DRAM_CAS_N SDRAM Column Address Strobe
DRAM_CKE SDRAM Clock Enable
DRAM_CLK SDRAM Clock
DRAM_WE_N SDRAM Write Enable
DRAM_CS_N SDRAM Chip Select

Signal NameDescription
SRAM_ADDR[17:0] SRAM Address[17:0]
SRAM_DQ[15:0] SRAM Data[15:0]
SRAM_WE_N SRAM Write Enable
SRAM_OE_N SRAM Output Enable
SRAM_UB_N SRAM High-byte Data Mask
SRAM_LB_N SRAM Low-byte Data Mask
SRAM_CE_N SRAM Chip Enable

Signal NameDescription
FL_ADDR[21:0] FLASH Address[21:0]
FL_DQ[7:0] FLASH Data[7:0]
FL_CE_N FLASH Chip Enable
FL_OE_N FLASH Output Enable
FL_RST_N FLASH Reset
FL_WE_N FLASH Write Enable

See DE2_pin_assignments.csv, a comma-delimited file that matches "standard" descriptive names to actual FPGA pin locations. This file can be directly opened in Microsoft Excel.

References

SDRAM datasheet

SRAM datasheet

Flash Memory datasheet

   DE2 User Manual, version 1.4, 2006. (pdf)


Maintained by John Loomis, last updated 28 April 2007