39
FUNCTIONAL BLOCK DIAGRAM
Bank Select
CLK
ADD
LRAS
Address Register
Row Decoder
Sense AMP
Output Buffer
I/O Control
Col. Buffer
Row Buffer
Refresh Counter
LCBR
LCKE
LRAS
CLK
CKE
CS
RAS
CAS
WE
L(U)DQM
LCBR
LWE
LCAS
LWCBR
LDQM
LWE
LDQM
DQi
Data Input Register
Column Decoder
Latency & Burst Length
Programming Register
512 x 16
512 x 16
Timing Register
Pin Name
Input
Function
CLK
System Clock
Active on the positive going edge to sample all inputs.
CS
Chip Select
Disables or enables device operation by masking or enabling all inputs except CLK, CKE
and L(U)DQM.
CKE
Clock Enable
Masks system clock to freeze operation from the next clock cycle.
CKE should be enabled at least one cycle prior to new command.
Disable input buffers for power down in standby.
A0~A10/AP
Address
Row/column addresses are multiplexed on the same pins.
Row address : RA0~RA10, column address : CA0~CA7.
BA
Bank Select Address
Selects bank to be activated during row address latch time.
Selects bank for read/write during column address latch time.
RAS
Row Address Strobe
Latches row addresses on the positive going edge of the CLK with RAS low.
Enables row access & precharge.
CAS
Column Address Strobe
Latches column addresses on the positive going edge fof the CLK with CAS low.
Enables column access.
WE
Write Enable
Enable write operation and row precharge.
Latches data in starting from CAS, WE active.
L(U)DQM
Data Input/Output Mask
Make data output Hi-Z, tSHZ after the clock and masks the output.
Blocks data input when L(U)DQM active.
DQ0~15
Data Input/Output
Data inputs/outputs are multiplexed on the same pins.
VDD/VSS
Power Supply/Ground
Power and ground for the input buffers and the core logic.
VDDQ/VSSQ Data Output Power/Ground Isolated power supply and ground for the output buffers to provide inproved noise
immunity.
N.C/RFU
No Connection/
This pin is recommended to be left No Connection on the device.
Reserved for Future Use
•
Pin Function Description