K4Y50164UC Datasheet, PDF (17/76 Pages) Samsung semiconductor – 512Mbit XDR TM DRAM(C-die)

K4Y50164UC
K4Y50084UC
K4Y50044UC
K4Y50024UC
XDR^TM DRAM
7.3 Request Packet Interactions
A summary of request packet interaction is shown in Table8. Each case is limited to request packets with commands that perform
memory operations(including refresh commands). This includes all commands in ROWA, ROWP, COL, and COLM packets. The
commands in COLX packets are described in later sections. See “Maintenance Operations” on page 42.
Request packet/command “a” is followed by request/ command “b”. The minimum possible spacing between these two packet/command
is 0*t_CYCLE. However, a larger time interval may be needed because of a resource interaction between the two packet/commands. If the
minimum possible sapcing is 0*t_CYCLE, then an entry of “No limit” is shown in the table.
Note that the spacing values shown in the table are relative to the effective beginning of a packet/command. The use of the delay field
with a command will delay the position of the effective packet/command from the position of the actual packet/command. See “Dynamic
Request Scheduling” on page 23 .
Any of the packet/command encoding under one of the four operation types is equivalent in terms of the resource constraints. Therefore.
both the horisontal columns(packet “a”) and vertical rows(packet “b”) of the interaction table are divided into four major groups.
The four possible operation types for request packet a and b include :
: [A] Active Row
ROWA/ACT
ROWP/REFA
ROWP/REFI
: [R] Read Column COL/RD
: [W] Write Column COL/WR
COLM/WRM
: [P] Precharge Row ROWP/PRE
ROWP/REFP
Table 8 : Packet Interaction Summary
Second packet/command to bank Bb
First packet/command to bank Ba
Activate Row [A]
ROWA - ACT Bb
ROWP - REFA Bb
ROWP - REFI Ba
Read Column [R] Write Column [W]
COL - RD Bb
COL - WR Bb
COLM - WRM Bb
Precharge Row [P]
ROWP - PRE Bb
ROWP - REFP Bb
Activate Row [A]
ROWA - ACT Ba
ROWP - REFA Ba
ROWP - REFI Ba
Ba,Bb different
Ba,Bb same
Case AAd: t_RR
Case AAs: t_RC
Case ARd: No limit Case AWd: No limit
Case ARs: t_RCD-R Case AWs: t_RCD-W
Case APd: No limit
Case APs: t_RAS
Read Column [R] ^{Ba,Bb different}
COL - RD Ba
Ba,Bb same
Write Column [W] Ba,Bb different
COL - WR Ba
COLM - WRM Ba ^{Ba,Bb same}
Precharge Row [P] ^{Ba,Bb different}
ROWP - PRE Ba
ROWP - REFP Ba
Ba,Bb same
See Examples:
Case RAd: No limit Case RRd: t_CC
Case RWd:^a t_∆RW
Case RPd: No limit
Case RAs:^b t_RDP+t_RP ^{Case RRs: t}CC
Case RWs: ^a t_∆RW
Case RPs: t_RDP
Case WAd: No limit Case WRd:^c t_∆WR Case WWd: t_CC
Case WPd: No limit
Case WAs^b:t_WRP+t_RP Case WRs:^c t_∆WR
Case WWs: t_CC
Case WPs: t_WRP
Case PAd: No limit Case PRd: No limit Case PWd: No limit
Case PPd: t_PP
Case PAs: t_RP
Figure 4
Case PRs:^d t_RP+t_{RCD- Case PWs:d tRP+tRCD-W Case PPs: tRC}
R
Figure 5
Figure 6
Figure 7
a. t_∆RW is equal to t_CC + t_{RW-BUB,XDRDRAM}+ t_CAC - t_CWD and is defined in Table 18. This also depends upon propagation delay - See “Propagation Delay” on page 32.
b. A PRE command is needed between the RD and ACT/REFA commands or the WR/WRM and ACT/REFA commands.
c. t_∆RW is defined in Table 18.
d. An ACT command is needed between the PRE/REFP and RD commands or the PRE/REFP and WR/WRM commands.
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Rev. 1.1 August 2006