ic42s32800 ETC-unknow, ic42s32800 Datasheet - Page 12

• Manufacturer Part Number: ic42s32800
• Description: 2m X 32 Bit X 4 Banks 256-mbit Sdram
• Manufacturer: ETC-unknow

IC42S32800
IC42S32800L
12
CLK
COMMAND
DQ’s
CLK
COMMAND
CAS# latency=2
t CK2 , DQ’s
Note:The DQMs can remain low in this example if the length of the write burst is 1 or 2.
CAS# latency=3
t CK3 , DQ’s
CLK
DQM
COMMAND
ADDRESS
DQ
The Read command that interrupts a write burst without auto precharge function should be issued one cycle after
the clock edge in which the last data-in element is registered.In order to avoid data contention,input data must
be removed from the DQs at least one clock cycle before the first read data appears on the outputs (refer to the
following figure).Once the Read command is registered,the data inputs will be ignored and writes will not be
executed.
The BankPrecharge/PrechargeAll command that interrupts a write burst without the auto precharge function
should be issued m cycles after the clock edge in which the last data-in element is registered,where m equals tWR/
tCK rounded up to the next whole number.In addition,the DQM signals must be used to mask input data,starting
with the clock edge following the last data-in element and ending with the clock edge on which the BankPrecharge/
PrechargeAll command is entered (refer to the following figure).
: don t care
Write Interrupted by a Write (Burst Length =4,CAS#Latency =2,3)
Write Interrupted by a Read (Burst Length =4,CAS#Latency =2,3)
T0
T0
NOP
NOP
BANK
COL n
WRITE
DIN
T0
n
Input data for the write is masked.
WRITEA
WRITEA
DIN A 0
T 1
T1
DIN A 0
DIN A 0
1 Clk Interval
NOP
n + 1
T1
t WR
WRITEB
READ B
DIN B 0
don’t care
don’t care
T2
T2
Precharge
BANK (S)
T2
Write to Precharge
DIN B 1
don’t care
T3
T3
NOP
NOP
NOP
DI N
T3
DIN B 2
T4
NOP
T4
NOP
t RP
DOUT B 0
NOP
Input data must be removed from the DQs at least one clock
cycle before the Read data appears on the outputs to avoid
data contention.
T4
DIN B 3
T5
T5
NOP
NOP
DOUT B 0
DOUT B 1
Activate
ROW
T5
T6
Integrated Circuit Solution Inc.
NOP
T6
NOP
DOUT B 2
DOUT B 1
NOP
T6
T7
T7
NOP
DOUT B 3
NOP
DOUT B 2
DR046-0B 12/21/2004
T8
NOP
T8
NOP
DOUT B 3