ESMT
M13S2561616A (2S)
Operation Temperature Condition -40°C~85°C
Extended Mode Register Set (EMRS)
The extended mode register stores the data enabling or disabling DLL, and selecting output drive strength. The default value of
the extended mode register is not defined, therefore the extended mode register must be written after power up for enabling or
disabling DLL. The extended mode register is written by asserting low on CS , RAS , CAS , WE and high on BA0 (The DDR
SDRAM should be in all bank precharge with CKE already high prior to writing into the extended mode register). The state of
address pins A0~A12 and BA0~BA1 in the same cycle as CS , RAS , CAS and WE going low is written in the extended
mode register. Two clock cycles are requested to complete the write operation in the mode register. The mode register contents
can be changed using the same command and clock cycle requirements during operation as long as all banks are in the idle
state. A0 is used for DLL enable or disable. A1 and A6 are used for selecting output drive strength. “High” on BA0 is used for
EMRS. All the other address pins except A0~A1, A6 and BA0 must be set to low for proper EMRS operation. Refer to the table
for specific codes.
Address Bus
BA1 BA0 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
Extended Mode Register
0
1
RFU
DS
RFU
DS DLL
A6
A1
0
Drive Strength
A0
DLL Enable
Enable
0
0
1
1
Normal
Weak
RFU
0
1
1
Disable
0
1
Matched impedance
BA1 BA0 Operating Mode
0
0
0
1
MRS Cycle
EMRS Cycle
Note: RFU (Reserved for future use) must stay “0” during EMRS cycle.
Elite Semiconductor Memory Technology Inc.
Publication Date : Jan. 2015
Revision : 1.0 15/49
ESMT [ ELITE SEMICONDUCTOR MEMORY TECHNOLOGY INC. ]
