CMOS SDRAM Samsung Electronics, CMOS SDRAM Datasheet - Page 8

• Manufacturer Part Number: CMOS SDRAM
• Description: CMOS SDRAM Device Operations
• Manufacturer: Samsung Electronics

DEVICE OPERATIONS
E. BASIC FEATURE AND FUNCTION DESCRIPTIONS
1. CLOCK Suspend
2. DQM Operation
*Note : 1. CKE to CLK disable/enable = 1CLK.
DQ(CL2)
DQ(CL3)
DQ(CL2)
DQ(CL3)
1) Clock Suspended During Write (BL=4)
1) Write Mask (BL=4)
3) DQM with Clock Suspended (Full Page Read)
Internal
DQ(CL2)
DQ(CL3)
CMD
CMD
DQM
CKE
CKE
CKE
2. DQM makes data out Hi-Z after 2CLKs which should masked by CKE " L"
3. DQM masks both data-in and data-out.
CLK
CLK
CMD
DQM
CLK
ELECTRONICS
RD
WR
WR
D
D
D
D
0
0
0
0
D
D
D
D
1
1
1
1
DQM to Data-in Mask = 0
Q
Not Written
0
Masked by CKE
Masked byDQM
D
D
D
D
2
2
3
3
Hi-Z
Hi-Z
D
D
Note 2
3
3
Q
Q
2
1
DQ(CL2)
DQ(CL3)
Internal
DQ(CL3)
DQ(CL2)
2) Clock Suspended During Read (BL=4)
2) Read Mask (BL=4)
CMD
CKE
CKE
CLK
CMD
DQM
Hi-Z
Hi-Z
CLK
Q
Q
4
3
RD
RD
Hi-Z
Hi-Z
Q
Q
0
Q
Q
0
6
5
Hi-Z
Hi-Z
D
Q
Q
0
Q
Q
1
0
Masked by DQM
7
6
Rev. 0.2 Sep. 1999
Q
Q
Q
Q
Suspended Dout
2
1
CMOS SDRAM
Masked by CKE
DQM to Data-out Mask = 2
Q
Q
8
7
2
1
Q
Q
3
2
Q
Q
Q
3
2
3
Q
3