k4r881869m Samsung Semiconductor, Inc., k4r881869m Datasheet - Page 16

• Manufacturer Part Number: k4r881869m
• Description: 288mbit Rdram 512k X 18 Bit X 2*16 Dependent Banks Direct Rdramtm
• Manufacturer: Samsung Semiconductor, Inc.

K4R881869M
COL-to-COL Packet Interaction
Figure 8 shows three arbitrary packets on the COL pins.
Packets “b” and “c” must be separated by an interval
t
values in all three packets. Table 12 summarizes the
t
Cases CC1 through CC5 summarize the rules for every situ-
ation other than the case when COPb is a WR command and
COPc is a RD command. In CC3, when a RD command is
followed by a WR command, a gap of t
inserted between the two COL packets. See Figure 4 for
more explanation of why this gap is needed. For cases CC1,
CCDELAY
CCDELAY
Case #
CC1
CC2
CC3
CC4
CC5
CC6
CC7
CC8
CC9
CC10
CTM/CFM
COL4
DQA8..0
ROW2
DQB8..0
..COL0
Figure 8: COL-to-COL Packet Interaction- Timing
..ROW0
COPa
xxxx
xxxx
xxxx
xxxx
xxxx
WR
WR
WR
NOCOP
RD
which depends upon the command and address
values for all possible cases.
T
COPa a1
0
Transaction a: COPa
Transaction b: COPb
Transaction c: COPc
T
Da
xxxxx
xxxxx
xxxxx
xxxxx
xxxxx
== Db
== Db
/= Db
== Db
== Db
1
T
t
2
CCDELAY
T
3
T
COPb b1
4
Ba
x..x
x..x
x..x
x..x
x..x
x
x
x
x
x
T
5
T
6
T
Ca1
x..x
x..x
x..x
x..x
x..x
x..x
x..x
x..x
x..x
x..x
7
T
8
T
Table 12: COL-to-COL Packet Interaction - Rules
9
COPb
NOCOP
RD,WR
RD
RD
WR
WR
WR
WR
WR
WR
T
10
b1 = {Db,Bb,Cb1}
a1 = {Da,Ba,Ca1}
c1 = {Dc,Bc,Cc1}
CAC
T
11
T
12
COPc c1
T
-t
13
CWD
T
Db
Db
Db
Db
Db
Db
Db
Db
Db
Db
Db
14
T
15
T
must be
16
Bb
Bb
Bb
Bb
Bb
Bb
Bb
Bb
Bb
Bb
Bb
T
17
T
18
T
Cb1 COPc
Cb1
Cb1
Cb1
Cb1
Cb1
Cb1
Cb1
Cb1
Cb1
Cb1
19
Page 14
T
xxxx
NOCOP
WR
RD
WR
RD
RD
RD
RD
RD
CC2, CC4, and CC5, there is no restriction (t
t
In cases CC6 through CC10, COPb is a WR command and
COPc is a RD command. The t
between these two packets depends upon the command and
address in the packet with COPa. In particular, in case CC6
when there is WR-WR-RD command sequence directed to
the same device, a gap will be needed between the packets
with COPb and COPc. The gap will need a COLC packet
with a NOCOP command directed to any device in order to
force an automatic retire to take place. Figure 18 (right)
provides a more detailed explanation of this case.
In case CC10, there is a RD-WR-RD sequence directed to
the same device. If a prior write to the same device is unre-
tired when COPa is issued, then a gap will be needed
between the packets with COPb and COPc as in case CC6.
The gap will need a COLC packet with a NOCOP command
directed to any device in order to force an automatic retire to
take place.
Cases CC7, CC8, and CC9 have no restriction (t
t
For the purposes of analyzing COL-to-ROW interactions,
the PREC, WRA, and RDA commands of the COLC packet
are equivalent to the NOCOP, WR, and RD commands.
These commands also cause a precharge operation PREC to
take place. This precharge may be converted to an equiva-
lent PRER command on the ROW pins using the rules
summarized in Figure 14.
CC
CC
).
).
Dc
xxxxx
xxxxx
xxxxx
xxxxx
xxxxx
== Db
/= Db
== Db
== Db
== Db
Bc
x..x
x..x
x..x
x..x
x..x
x..x
x..x
x..x
x..x
x..x
Cc1
x..x
x..x
x..x
x..x
x..x
x..x
x..x
x..x
x..x
x..x
t
t
t
t
t
t
t
t
t
t
t
CC
CC
CC
CC
CC
RTR
CC
CC
CC
CC
CCDELAY
Preliminary
Direct RDRAM
Rev. 0.9 Jan. 2000
CCDELAY
+t
CAC
-t
CWD
value needed
CCDELAY
CCDELAY
Example
Figure 4
Figure 15
Figure 16
Figure 18
is
™
is