
WED9LC6816V
8
White Electronic Designs Corporation (602) 437-1520 www.whiteedc.com
White Electronic Designs
September, 2003
Rev. 1
White Electronic Designs Corp. reserves the right to change products or specications without notice.
CLOCK FREQUENCY AND LATENCY PARAMETERS - 125MHZ SDRAM
(UNIT = NUMBER OF CLOCK)
CLOCK FREQUENCY AND LATENCY PARAMETERS - 100MHZ SDRAM
(UNIT = NUMBER OF CLOCK)
REFRESH CYCLE PARAMETERS
NOTES:
1.
4096 cycles
2.
Any time that the Refresh Period has been exceeded, a minimum of two Auto (CBR) Refresh commands must be given to "wake-up" the device.
SDRAM COMMAND TRUTH TABLE
NOTES:
1.
All of the SDRAM operations are dened by states of SDCE#, SDWE#, SDRAS#, SDCAS#, and BWE 0-3 at the positive rising edge of the clock.
2.
Bank Select (BA), A12 (BA0) and A13 (BA1) select between different banks.
3.
During a Burst Write cycle there is a zero clock delay, for a Burst Read cycle the delay is equal to the CAS latency.
4.
The BWE# has two functions for the data DQ Read and Write operations. During a Read cycle, when BWE# goes high at a clock timing the data outputs are disabled and
become high impedance after a two clock delay. BWE# also provides a data mask function for Write cycles. When it activates, the Write operation at the clock is prohibited
(zero clock latency).
Frequency
CAS
Latency
tRC
70ns
tRAS
50ns
tRP
20ns
tRRD
20ns
tRCD
20ns
tCCD
10ns
tCDL
10ns
tRDL
10ns
125MHz (8.0ns)
3
9
6
3
2
3
1
100MHz (10.0ns)
3
7
5
2
1
83MHz (12.0ns)
2
6
4
2
1
Frequency
CAS
Latency
tRC
70ns
tRAS
50ns
tRP
20ns
tRRD
20ns
tRCD
20ns
tCCD
10ns
tCDL
10ns
tRDL
10ns
100MHz (12.0ns)
3
7
5
2
1
83MHz (12.0ns)
2
6
5
2
1
Parameter
Symbol
-10
-12
Units
Min
Max
Min
Max
Refresh Period
(1,2)
tREF
—
64
—
64
ms
Function
SDCE#
SDRAS#
SDCAS#
SDWE#
BWE#
A12,
A13
SDA10 A11-0
Notes
Mode Register Set
L
X
OP CODE
Auto Refresh (CBR)
L
H
X
Precharge
Single Bank
L
H
L
X
BA
L
2
Precharge all
Banks
L
H
L
X
H
Bank Activate
L
H
X
BA
Row Address
2
Write
L
H
L
X
BA
L
2
Write with Auto Precharge
L
H
L
X
BA
H
2
Read
L
H
L
X
BA
L
2
Read with Auto Precharge
L
H
L
H
X
BA
H
2
Burst Termination
L
H
L
X
3
No Operation
L
H
X
Device Deselect
H
X
Data Write/Output Disable
X
L
X
4
Data Mask/Output Disable
X
H
X
4