M66257 Mitsubishi, M66257 Datasheet - Page 9

• Manufacturer Part Number: M66257
• Description: 5120 x 8-BIT x 2 LINE MEMORY (FIFO)
• Manufacturer: Mitsubishi

• Shortest read of data “n” written in cycle n
When the start of cycle n–1 on read side is earlier than the end of cycle n+1 on write side, output Q
In the figure shown below, the read of cycle n–1 is invalid.
• Longest read of data “n” written in cycle n: 1-line delay
Cycle n–1 on read side should be started after end of cycle n+1 on write side
Cycle n <1>* on read side should be started when cycle n <2>* on write is started
Output Qn of n cycle <1>* can be read until the start of reading side n cycle <1> and the start of writing side n cycle <2>* over-
lap each other.
WCK
RCK
WCK
RCK
D
D
Q
Q
n
n
n
n
(n–1)<1>*
(n–1)<0>*
Cycle n <1>*
Cycle n <0>*
Cycle n
(n)<1>*
(n)<0>*
(n)
Cycle n–2
Cycle n+1
(n+1)
Cycle 0 <2>*
Cycle 0 <1>*
Cycle n+2
Cycle n–1
(0) <2>*
(0)<1>*
invalid
(n+2)
Cycle n+3
5120
<0>*, <1>* and <2>* indicates a line value.
(n–1)<2>*
MITSUBISHI DIGITAL ASSP
8-BIT
(n–1)<1>*
Cycle n
(n+3)
n
of cycle n becomes invalid.
2 LINE MEMORY (FIFO)
Cycle n <2>*
Cycle n <1>*
(n)
M66257FP
(n)<2>*
(n)<1>*
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