K4R271669D Datasheet, PDF (17/20 Pages) Samsung semiconductor – 128Mbit RDRAM(D-die)

K4R271669D
Preliminary
Direct RDRAM^™
Timing Parameters
Parameter
t_RC
t_RAS
t_RP
t_PP
t_RR
t_RCD
t_CAC
t_CWD
t_CC
t_PACKET
t_RTR
t_OFFP
t_RDP
t_RTP
Table 13: Timing Parameter Summary
Min
Description
-45
-800
Row Cycle time of RDRAM banks -the interval between ROWA packets with
28
ACT commands to the same bank.
RAS-asserted time of RDRAM bank - the interval between ROWA packet with
20
ACT command and next ROWR packet with PRER^a command to the same bank.
Row Precharge time of RDRAM banks - the interval between ROWR packet
8
with PRER^a command and next ROWA packet with ACT command to the same
bank.
Precharge-to-precharge time of RDRAM device - the interval between succes-
8
sive ROWR packets with PRER^a commands to any banks of the same device.
RAS-to-RAS time of RDRAM device - the interval between successive ROWA
8
packets with ACT commands to any banks of the same device.
RAS-to-CAS Delay - the interval from ROWA packet with ACT command to
9
COLC packet with RD or WR command). Note - the RAS-to-CAS delay seen by
the RDRAM core (t_RCD-C) is equal to t_RCD-C = 1 + t_RCD because of differences
in the row and column paths through the RDRAM interface.
CAS Access delay - the interval from RD command to Q read data. The equation 8
for t_CAC is given in the TPARM register in Figure 40.
CAS Write Delay (interval from WR command to D write data.
6
CAS-to-CAS time of RDRAM bank - the interval between successive COLC
4
commands).
Length of ROWA, ROWR, COLC, COLM or COLX packet.
4
Interval from COLC packet with WR command to COLC packet which causes
8
retire, and to COLM packet with bytemask.
The interval (offset) from COLC packet with RDA command, or from COLC
4
packet with retire command (after WRA automatic precharge), or from COLC
packet with PREC command, or from COLX packet 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 with
4
PRER.
Interval from last COLC packet with automatic retire command to ROWR packet 4
with PRER.
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.
Max
Units
-
64µs^b
t_CYCLE
t_CYCLE
-
t_CYCLE
-
t_CYCLE
-
t_CYCLE
-
t_CYCLE
12
t_CYCLE
6
t_CYCLE
-
t_CYCLE
4
t_CYCLE
-
t_CYCLE
4
t_CYCLE
-
t_CYCLE
-
t_CYCLE
Figure(s)
Figure 16
Figure 17
Figure 16
Figure 17
Figure 16
Figure 17
Figure 13
Figure 14
Figure 16
Figure 17
Figure 5
Figure 40
Figure 5
Figure 16
Figure 17
Figure 3
Figure 18
Figure 15
Figure 40
Figure 16
Figure 17
Page 15
Version 1.0 Dec. 2001