W988D6FB_13 Datasheet, PDF (25/66 Pages) Winbond – 256Mb Mobile LPSDR

W988D6FB / W988D2FB
256Mb Mobile LPSDR
9.3.3 READ with auto precharge interrupted by a WRITE (with or without auto precharge)
A WRITE to bank m will interrupt a READ on bank n when registered. DQM should be used two clocks prior to the
WRITE command to prevent bus contention. The precharge to bank n begins when the WRITE to bank m is
registered.
T0
T1
T2
T3
T4
T5
T6
T7
CLK
Command
READ-AP
Bank n
NOP
NOP
Internal
states
Bank n ^Page
active
Bank m
READ with burst of 4
Page active
NOP
WRITE-AP
Bank m
NOP
NOP
Interrupt burst, precharge
tRP-bank n
WRITE with burst of 4
NOP
Idle
tWR-bank m
Write-back
Address
DQM ¹
DQ
Bank n,
Col a
CL=3 (bank n)
Bank m,
Col d
DOUT
Din
a
d
Din
Din
d+1
d+2
Note: 1. DQM is HIGH at T2 to prevent D_OUTa + 1 from contending with D_INd at T4.
Din
d+3
Don’t Care
9.3.4 WRITE with auto precharge interrupted by a READ (with or without auto precharge)
A READ to bank m will interrupt a WRITE on bank n when registered, with the data-out appearing CL later. The precharge to bank
n will begin after tWR is met, where tWR begins when the READ to bank m is registered. The last valid WRITE to bank n will be
data in registered one clock prior to the READ to bank m.
T0
T1
T2
T3
T4
T5
T6
T7
CLK
Command
Internal
states
Bank n
Bank m
NOP
WRITE-AP
Bank n
NOP
READ-AP
Bank m
NOP
NOP
NOP
Page active
WRITE with burst of 4
Page active
Interrupt burst, write-back
tWR-bank n
precharge
tRP-bank n
READ with burst of 4
NOP
tRP-bank m
Address
DQ
Bank n,
Col a
Din
a
Din
a+1
Note: 1. DQM is LOW.
Bank m,
Col d
CL=3 (bank m)
Dout
d
Dout
d+1
Don’t Care
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Publication Release Date : August 15, 2013
Revision A01-004