W3H64M72E-XSBX
White Electronic Designs
ADVANCED*
FIGURE 9 – EXTENDED MODE REGISTER 3 (EMR3) DEFINITION
BA2 BA1 BA0 A13 A12 A11 A10 A9 A8 A7 A 6 A5 A4 A3 A2 A1 A0
Address Bus
Exten ded Mo de
Register (Ex)
16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
01
01 01 01 01 01 01 01 01 01 01 01
01 01
EMR3
Mode Register Definition
M1 6 M15 M14
Mode register (MR)
0
1
0
1
0
0
0
0
0
0
1
1
Extended mode register (EMR)
Extended mode register (EMR2)
Extended mode register (EMR3)
Note: 1. E13 (A13)-E0 (A0) are reserved for future use and must be programmed to
"0." A13 is not used in this device.
EXTENDED MODE REGISTER 2
not alter the contents of the memory array, provided it is
performed correctly.
ꢀhe extended mode register 2 (EMR2) controls functions
beyond those controlled by the mode register. Currently
all bits in EMR2 are reserved, as shown in Figure 8. ꢀhe
EMR2 is programmed via the TM command and will
retain the stored information until it is programmed again
or the device loses power. Reprogramming the EMR will
not alter the contents of the memory array, provided it is
performed correctly.
EMR3 must be loaded when all banks are idle and no
bursts are in progress, and the controller must wait the
t
specified time MRD before initiating any subsequent
operation. Violating either of these requirements could
result in unspecified operation.
Bit E7 (A7) must be programmed as"1" to provide a faster
refresh rate on devices if the ꢀCASE exceeds 85°C
COMMAND TRUTH TABLES
ꢀhe following tables provide a quick reference of DDR2
SDRAM available commands, including CKE power-down
modes, and bank-to-bank commands.
EMR2 must be loaded when all banks are idle and no
bursts are in progress, and the controller must wait the
t
specified time MRD before initiating any subsequent
operation. Violating either of these requirements could
result in unspecified operation.
EXTENDED MODE REGISTER 3
ꢀhe extended mode register 3 (EMR3) controls functions
beyond those controlled by the mode register. Currently,
all bits in EMR3 are reserved, as shown in Figure 9.
ꢀhe EMR3 is programmed via the TM command and will
retain the stored information until it is programmed again
or the device loses power. Reprogramming the EMR will
White Electronic Designs Corp. reserves the right to change products or specifications without notice.
March 2006
Rev. 1
15
White Electronic Designs Corporation • (602) 437-1520 • www.wedc.com
WEDC [ WHITE ELECTRONIC DESIGNS CORPORATION ]
