IS43R16800A-6T ISSI [Integrated Silicon Solution, Inc], IS43R16800A-6T Datasheet - Page 13

• Manufacturer Part Number: IS43R16800A-6T
• Description: 8Meg x 16 128-MBIT DDR SDRAM
• Manufacturer: ISSI [Integrated Silicon Solution, Inc]

IS43R16800A-6
EXTENDED MODE REGISTER DEFINITION
The Extended Mode Register is a second register to
enable additional functions of the DDR SDRAM. This
register is loaded as a step in the normal initialization
of the device. The Load Extended Mode Register
command samples the values on inputs A0-A11, BA0
(High) and BA1 (Low) and stores them as register
values E0-E13. The additional functions are DLL
enable/disable and output drive strength. Similarly to
the Load Mode Register, the Load Extended Mode
Register has reserved bit values, a bank idle pre-
requisite, and a tMRD time requirement. The data in
the mode register is retained until it is reloaded or the
device loses its power.
EXTENDED MODE REGISTER DEFINITION
Integrated Silicon Solution, Inc. — 1-800-379-4774
Rev. 00A
04/04/06
Operating Mode
E13
—
0
BA1 BA0 A11 A10
E12
—
1
E11
—
0
E10
—
0
E9
—
0
A9
E8
—
0
Drive Strength
A8
E6
—
0
0
E7
—
0
A7
E5
—
0
0
Mode
Standard Operation
All Other States Reserved
A6
E4
—
0
0
A5
DLL Enable/Disable
When the Load Extended Mode Register command is
issued, DLL should be enabled (E0 = 0). Normal
operation of the device requires this, but DLL can be
disabled for debugging or evaluation, if necessary.
Output Drive Strength
Normal drive strength for the outputs is specified as
SSTL 2. However, there is an option for reduced drive
strength included.
E3
—
0
0
A4
E2
—
A3
0
0
A2
E1
—
0
1
A1
Type
Full Strength
Weak
All Other States Reserved
DLL
A0
E0
0
1
Address Bus (Ax)
Mode Register (Ex)
Status
Enable
Disable
ISSI
13
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