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Leon2 memory controller
CONFIG_MCTRL_LEON2
  Say Y here to enable the LEON2 memory controller. The controller
  can access PROM, I/O, SRAM and SDRAM. The bus width for PROM
  and SRAM is programmable to 8-, 16- or 32-bits.

8-bit memory support
CONFIG_MCTRL_8BIT
  If you say Y here, the PROM/SRAM memory controller will support
  8-bit mode, i.e. operate from 8-bit devices as if they were 32-bit.
  Say N to save a few hundred gates.

16-bit memory support
CONFIG_MCTRL_16BIT
  If you say Y here, the PROM/SRAM memory controller will support
  16-bit mode, i.e. operate from 16-bit devices as if they were 32-bit.
  Say N to save a few hundred gates.

Write strobe feedback
CONFIG_MCTRL_WFB
  If you say Y here, the PROM/SRAM write strobes (WRITEN, WEN) will
  be used to enable the data bus drivers during write cycles. This
  will guarantee that the data is still valid on the rising edge of
  the write strobe. If you say N, the write strobes and the data bus
  drivers will be clocked on the rising edge, potentially creating
  a hold time problem in external memory or I/O. However, in all
  practical cases, there is enough capacitance in the data bus lines
  to keep the value stable for a few (many?) nano-seconds after the
  buffers have been disabled, making it safe to say N and remove a 
  combinational path in the netlist that might be difficult to 
  analyze.

Write strobe feedback
CONFIG_MCTRL_5CS
  If you say Y here, the 5th (RAMSN[4]) SRAM chip select signal will
  be enabled. If you don't intend to use it, say N and save some gates.

SDRAM controller enable
CONFIG_MCTRL_SDRAM
  Say Y here to enabled the PC100/PC133 SDRAM controller. If you don't
  intend to use SDRAM, say N and save about 1 kgates.

SDRAM controller inverted clock
CONFIG_MCTRL_SDRAM_INVCLK
  If you say Y here, the SDRAM controller output signals will be delayed
  with 1/2 clock in respect to the SDRAM clock. This will allow the used
  of an SDRAM clock which in not strictly in phase with the internal 
  clock. This option will limit the SDRAM frequency to 40 - 50 MHz.

  On FPGA targets without SDRAM clock synchronizations through PLL/DLL, 
  say Y. On ASIC targets, say N and tell your foundry to balance the 
  SDRAM clock output.

SDRAM separate address buses
CONFIG_MCTRL_SDRAM_SEPBUS
  Say Y here if your SDRAM is connected through separate address
  and data buses (SA & SD). This is the case on the GR-CPCI-XC2V6000
  board, but not on the GR-PCI-XC2V3000 or Avnet XCV1500E boards.

64-bit data bus
CONFIG_MCTRL_SDRAM_BUS64
  Say Y here to enable 64-bit SDRAM data bus.

Page burst enable
CONFIG_MCTRL_PAGE
  Say Y here to enable SDRAM page burst operation. This will implement
  read operations using page bursts rather than 8-word bursts and save
  about 500 gates (100 LUTs). Note that not all SDRAM supports page 
  burst, so use this option with care.

Programmable page burst enable
CONFIG_MCTRL_PROGPAGE
  Say Y here to enable programmable SDRAM page burst operation. This
  will allow to dynamically enable/disable page burst by setting
  bit 17 in MCFG2.