MT46V64M16P-6T IT:A Micron, MT46V64M16P-6T IT:A Datasheet - Page 46

• Manufacturer Part Number: MT46V64M16P-6T IT:A
• Description: DRAM Chip DDR SDRAM 1G-Bit 64Mx16 2.5V 66-Pin TSOP Tray
• Manufacturer: Micron

REGISTER DEFINITION
Mode Register
Figure 21:
PDF: 09005aef80768abb/Source: 09005aef82a95a3a
DDR_x4x8x16_Core2.fm - 1Gb DDR: Rev. J; Core DDR Rev. E 7/11 EN
Mode Register Definition
Notes:
Mn + 2
The mode register is used to define the specific DDR SDRAM mode of operation. This
definition includes the selection of a burst length, a burst type, a CAS latency, and an
operating mode, as shown in Figure 21. The mode register is programmed via the LMR
command (with BA0 = 0 and BA1 = 0) and will retain the stored information until it is
programmed again or until the device loses power (except for bit A8, which is self-
clearing).
Reprogramming the mode register will not alter the contents of the memory, provided it
is performed correctly. The mode register must be loaded (reloaded) when all banks are
idle and no bursts are in progress, and the controller must wait the specified time before
initiating the subsequent operation. Violating either of these requirements will result in
unspecified operation.
Mode register bits A[2:0] specify the burst length, A3 specifies the type of burst (sequen-
tial or interleaved), A[6:4] specify the CAS latency, and A[n:7] specify the operating
mode.
1. n is the most significant row address bit from Table 2 on page 2.
Mn
0
0
–
0
0
1
1
. . .
0
0
–
Mn + 1
M9
0
1
0
1
0
0
–
M8
n + 2
0
1
–
Mode Register Definition
Base mode register
Extended mode register
Reserved
Reserved
0
M7
0
0
–
BA1
n + 1
0
M6–M0
Valid
Valid
BA0
–
n 1
Operating mode
An
Operating Mode
Normal operation
Normal operation/reset DLL
All other states reserved
. . .
. . .
46
9
A9
8
A8
Micron Technology, Inc., reserves the right to change products or specifications without notice.
7
A7 A6 A5 A4 A3
CAS Latency BT
6
M3
0
1
5
Burst Type
Interleaved
Sequential
4
1Gb: x4, x8, x16 DDR SDRAM
3
Burst length
2
A2 A1 A0
M6
0
0
0
0
1
1
1
1
1
M2
0
0
0
0
1
1
1
1
M5
©2000 Micron Technology, Inc. All rights reserved.
0
0
1
1
0
0
1
1
0
M1
0
0
1
1
0
0
1
1
M4
0
1
0
1
0
1
0
1
Address bus
Mode register
(Mx)
M0
0
1
0
1
0
1
0
1
CAS Latency
3 (-5B only)
Burst Length
Reserved
Reserved
Reserved
Reserved
Reserved
Operations
Reserved
Reserved
Reserved
Reserved
Reserved
2.5
2
2
4
8