
=
The above information is the exclusive intellectual property of Winbond Electronics and shall not be disclosed, distributed or reproduced without permission from Winbond.
21
Versi on 0. 4, March/2000
can be accessed.
SDRAM mode : these signals are served as DQMB function, these are input mask signals for write
cycle and output enable signals for read cycle.
- MA[0:13] (out) :
These signals are used to provide the multiplexed row and column address to the EDO DRAM or
SDRAM.
- MD[0:31] (in/out) :
These signals are used to interface to the DRAM data bus.
- CKE (out) :
This signal are used to enable or disable MCLK into SDRAM.
- MCLK(out) :
This signal is SDRAM clock input, all SDRAM input /ouput signals are refrenced with MCLK rising
edge.
Operation Modes :
- MX1 Mode : Once DRAMTctrl2[2:3] is set to 00, memory controller frequency is same
as CPUCLK.
- MX1.5 Mode : Once DRAMTctrl2[2:3] is set to 01, Memory controller frequency is CPUCLK/1.5.
- MX2 Mode : Once DRAMTctrl2[2:3] is set to 10, Memory controller frequency is CPUCLK/2.
- MCLK skew control : The SDRAM's CLK and internal MEMC system clocks are adjustable for SDRAM
operating
in higher clock rate (larger than 80 MHz). Three bit groups are used to define these
clocks' skew,
1 SDRAM CLK and two internal MEMC system clock. Following are some suggested
setting
as SDRAM operated in different modes : (Refer to DRAMctrl definition for details)
A.
for MX1 :
B.
for MX1.5 :
C.
for MX2 :
Application Notes :
The MEMC supports both SDRAM and EDO-RAM, while only 32-bit data bus is available. When 64 bit
MA[0:11] lines into th DRAMs. it also indicates which bytes
DRAMctrl[9:11]
DRAMctrl[12:14]
DRAMTctrl[9:11]
= 110,
= 010,
= 001.
DRAMctrl[9:11]
DRAMctrl[12:14]
DRAMTctrl[9:11]
= 010,
= 010,
= 010.
DRAMctrl[9:11]
DRAMctrl[12:14]
DRAMTctrl[9:11]
= 110,
= 001,
= 110.