K4R571669D Datasheet, PDF (17/20 Pages) Samsung semiconductor – 256/288Mbit RDRAM(D-die)

K4R571669D/K4R881869D
Direct RDRAM^™
Timing Parameters
Table 13: Timing Parameter Summary
Parameter
Description
Min Min Min Min Min
-32P -32 -35 -40 -45 Max
-1066 -1066 -1066 -800 -800
Row Cycle time of RDRAM banks -the interval between ROWA pack-
t_RC
ets with ACT commands to the same bank.
28 28 32 28 28
-
RAS-asserted time of RDRAM bank - the interval between ROWA
t_RAS
packet with ACT command and next ROWR packet with PRER^a com- 20 20 22 20 20 64µs^b
mand to the same bank.
Row Precharge time of RDRAM banks - the interval between ROWR
t_RP
packet with PRER^a command and next ROWA packet with ACT com- 8 8 10 8 8
-
mand to the same bank.
Precharge-to-precharge time of RDRAM device - the interval between
t_PP
successive ROWR packets with PRER^a commands to any banks of the 8 8 8 8 8
-
same device.
RAS-to-RAS time of RDRAM device - the interval between successive
t_RR
88888
-
ROWA packets with ACT commands to any banks of the same device.
RAS-to-CAS Delay - the interval from ROWA packet with ACT com-
mand to COLC packet with RD or WR command). Note - the RAS-to-
t_RCD
CAS delay seen by the RDRAM core (t_RCD-C) is equal to t_RCD-C = 1 + 9
9
9
7
9
-
t_RCD because of differences in the row and column paths through the
RDRAM interface.
t_CAC
t_CWD
t_CC
CAS Access delay - the interval from RD command to Q read data. The
89988
12
equation for t_CAC is given in the TPARM register in Figure 40.
CAS Write Delay (interval from WR command to D write data.
66666
6
CAS-to-CAS time of RDRAM bank - the interval between successive
44444
-
COLC commands).
t_PACKET Length of ROWA, ROWR, COLC, COLM or COLX packet.
44444
4
Interval from COLC packet with WR command to COLC packet which
t_RTR
causes retire, and to COLM packet with bytemask.
88888
-
The interval (offset) from COLC packet with RDA command, or from
COLC packet with retire command (after WRA automatic precharge),
t_OFFP
or from COLC packet with PREC command, or from COLX packet
44444
4
with PREX command to the equivalent ROWR packet with PRER. The
equation for t_OFFP is given in the TPARM register in Figure 40.
Interval from last COLC packet with RD command to ROWR packet
t_RDP
with PRER.
44444
-
Interval from last COLC packet with automatic retire command to
t_RTP
ROWR packet with PRER.
44444
-
Units Figure(s)
Figure 16
t_{CYCLE Figure 17}
Figure 16
t_{CYCLE Figure 17}
Figure 16
t_{CYCLE Figure 17}
t_CYCLE Figure 13
t_CYCLE Figure 14
Figure 16
t_{CYCLE Figure 17}
t_CYCLE
t_CYCLE
t_CYCLE
t_CYCLE
t_CYCLE
Figure 5
Figure 40
Figure 5
Figure 16
Figure 17
Figure 3
Figure 18
Figure 15
t_{CYCLE Figure 40}
t_CYCLE Figure 16
t_CYCLE Figure 17
a. Or equivalent PREC or PREX command. See Figure 15.
b. This is a constraint imposed by the core, and is therefore in units of µs rather than t_CYCLE.
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Version 1.4 July 2002