PD488588 Datasheet, PDF (30/79 Pages) Elpida Memory – 288M bits Direct Rambus DRAM

µPD488588
17. Interleaved Read - Example
Figure 17-1 shows an example of interleaved read transactions. Transactions similar to the one presented in Figure
13-1 are directed to non-adjacent banks of a single RDRAM. The address sequence is identical to the one used in
the previous write example. The DQ data pins efficiency is also 100%. The only difference with the write example
(aside from the use of the RD command rather than the WR command) is the use of the PREX command in a COLX
packet to precharge the banks rather than the RDA command. This is done because the PREX is available for a
readtransaction but is not available for a masked write transaction.
Figure 17-1 Interleaved Read Transaction with Two Dualoct Data Length
T₀ T₁ T₂ T₃ T₄ T₅ T₆ T₇ T₈ T₉ T₁₀ T₁₁T₁₂T₁₃ T₁₄ T₁₅ T₁₆T₁₇ T₁₈ T₁₉ T₂₀T₂₁ T₂₂ T₂₃ T₂₄T₂₅ T₂₆ T₂₇T₂₈T₂₉ T₃₀ T₃₁ T₃₂T₃₃ T₃₄ T₃₅ T₃₆T₃₇ T₃₈ T₃₉ T₄₀T₄₁ T₄₂ T₄₃T₄₄T₄₅ T₄₆ T₄₇
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA8..0
DQB8..0
ACT a0
ACT b0
t_RC
ACT c0
ACT d0
Transaction e can use the
same bank as transaction a
ACT e0
ACT f0
RD z1
Q (x2)
t_RCD
RD z2 RD a1
PREX y3
Q (y1) Q (y2)
RD a2 RD b1
PREX z3
t_CAC
Q (z1) Q (z2)
RD b2 RD c1
PREX a3
Q (a1) Q (a2)
t_RR
RD c2 RD d1
PREX b3
Q (b1) Q (b2)
RDd2 RD e1
PREX c3
Q (c1) Q (c2)
RD e2
PREX d3
Q (d1)
Transaction y: RD
Transaction z: RD
Transaction a: RD
Transaction b: RD
Transaction c: RD
Transaction d: RD
Transaction e: RD
Transaction f: RD
y0 = {Da,Ba+4,Ry}
z0 = {Da,Ba+6,Rz}
a0 = {Da,Ba,Ra}
b0 = {Da,Ba+2,Rb}
c0 = {Da,Ba+4,Rc}
d0 = {Da,Ba+6,Rd}
e0 = {Da,Ba,Re}
f0 = {Da,Ba+2,Rf}
y1 = {Da,Ba+4,Cy1}
z1 = {Da,Ba+6,Cz1}
a1 = {Da,Ba,Ca1}
b1 = {Da,Ba+2,Cb1}
c1 = {Da,Ba+4,Cc1}
d1 = {Da,Ba+6,Cd1}
e1 = {Da,Ba,Ce1}
f1 = {Da,Ba+2,Cf1}
y2= {Da,Ba+4,Cy2}
z2= {Da,Ba+6,Cz2}
a2= {Da,Ba,Ca2}
b2= {Da,Ba+2,Cb2}
c2= {Da,Ba+4,Cc2}
d2= {Da,Ba+6,Cd2}
e2= {Da,Ba,Ce2}
f2= {Da,Ba+2,Cf2}
y3 = {Da,Ba+4}
z3 = {Da,Ba+6}
a3 = {Da,Ba}
b3 = {Da,Ba+2}
c3 = {Da,Ba+4}
d3 = {Da,Ba+6}
e3 = {Da,Ba}
f3 = {Da,Ba+2}
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Data Sheet E0039N30 (Ver. 3.0)