tc59lm814 TOSHIBA Semiconductor CORPORATION, tc59lm814 Datasheet - Page 29

• Manufacturer Part Number: tc59lm814
• Description: 256mbits Network Fcram1
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Command
AUTO-REFRESH TIMING (CL = 3, BL = 4)
(output)
(output)
DQS
CLK
CLK
CLK
DQ
Note: In case of CL = 3, I
WRA REF
Hi-Z
Hi-Z
RDA
I
When the Auto-Refresh operation is performed, the synthetic average interval of Auto-Refresh command
specified by t
t
t
than Read / Write operation.
RCD
REFI
REFI
0
= 1 cycle
t
is average interval time in 8 Refresh cycles that is sampled randomly.
is specified to avoid partly concentrated current of Refresh operation that is activated larger area
1
t
REFI
LAL
1
WRA REF
=
REFI
Total time of 8 Refresh cycle
I
RC
must be satisfied.
2
REFC
= 5 cycles
CL = 3
I
RAS
t
2
must be meet 15 clock cycles.
DESL
= 4 cycles
3
8
WRA REF
8 Refresh cycle
4
Q0 Q1 Q2 Q3
t
3
I
WRA
RCD
5
=
t
= 1 cycle
1
+ t
REF
2
6
+ t
3
+ t
Hi-Z
Hi-Z
4
t
7
8
+ t
7
TC59LM814/06CTG-50,-60
I
REFC
WRA REF
5
+ t
6
n − 1
= 15 cycles
+ t
DESL
7
+ t
t
8
8
n
2005-06-21 29/39
WRA REF
n + 1
WRA
RDA
or
MRS or
LAL or
n + 2
REF
Rev 1.2