lm9831 National Semiconductor Corporation, lm9831 Datasheet - Page 6

• Manufacturer Part Number: lm9831
• Description: 42-bit Color, 1200dpi Usb Image Scanner
• Manufacturer: National Semiconductor Corporation

Timing Diagrams
48MHz Internal Clock
48MHz Internal Clock
(t
(t
PERIOD
PERIOD
Read Operation
Write Operation
= 20.83ns)
= 20.83ns)
D0-D15
D0-D15
A0-A9
RAS
CAS
RAS
CAS
WR
RD
0
0
Row Address
Figure 2: DRAM Refresh (CAS before RAS)
t
WR SETUP
1
Figure 1: DRAM Read and Write
1
n
2
2
6
3
Column Address
t
RD SETUP
3
Data
4
4
n
Data
5
5
Row Address
6
6
t
t
RD HOLD
WR HOLD
0
0
n+1
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