PF38F2030W0YTQ2 Micron Technology Inc, PF38F2030W0YTQ2 Datasheet - Page 49

• Manufacturer Part Number: PF38F2030W0YTQ2
• Manufacturer: Micron Technology Inc

Specifications of PF38F2030W0YTQ2

• Operating Temperature (max): 85C
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

128-Mbit W18 Family with Synchronous PSRAM
Figure 31: Example of PSRAM Burst Interrupt
9.6.3
9.7
November 2007
Order Number: 311760-10
PSRAM Burst Termination
A burst access is terminated by bringing CE# high and maintaining high for minimum of
tCBPH.
In burst mode a refresh opportunity must be provided every tCSL period by
maintaining CE# high for minimum of 15ns or maintaining CE# high during a clock low
to high transition.
PSRAM Row Boundary Crossing
Row boundary crossings are not allowed in burst mode (regardless of using variable or
fixed latency mode.) An on-going burst must be terminated by the system prior to a
row boundary crossing. A row boundary crossing would never occur if the PSRAM is
operating in fixed burst length and wrap mode. Therefore the only time the system
should be concerned with row boundary crossing is if the PSRAM is operating with “no
wrap” (BCR3 = 0b) or “continuous burst length” (BCR[2:0] = 111b) settings.
In terminating bursts prior to row boundary crossing, the system may read the row size
(128 or 256 words) to determine at which addresses the row boundary crossing occurs.
If the system cannot do this, then it should be assumed that the row size is 128 words.
In the case of 128-word row size the boundary between adjacent rows occurs at every
address ending in 7Fh (111 1111 b.) In the case of 256-word row size the boundary
between adjacent rows occurs at every address ending in FFh (1111 1111 b.)
At a Row boundary crossing, a burst interrupt or termination must occur no later than
2-clock cycle past the transaction representing the last word of a row.
C L K
C o ntrol
A D V #
D Q
Burst Init
N o-O P
N o-O P
N o -O P
tH D
C ode 3
N o-O P
Burst Init
R ead b ecom es high -Z
Earliest allow ed
burst interrup t
W ritedataism asked
tW H Z
Datasheet
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