9

White Electronic Designs Corporation • (508) 366-5151 • www.whiteedc.com

WED9LC6416V

January 20001

Mode Register Set

L

L

L

L

X

OP CODE

Auto Refresh (CBR)

L

L

L

H

X

X

X

Precharge

Single Bank

L

L

H

L

X

BA

L

2

Precharge all Banks

L

L

H

L

X

X

H

Bank Activate

L

L

H

H

X

BA

Row Address

2

Write

L

H

L

L

X

BA

L

2

Write with Auto Precharge

L

H

L

L

X

BA

H

2

Read

L

H

L

L

X

BA

L

2

Read with Auto Precharge

L

H

L

H

X

BA

H

2

Burst Termination

L

H

H

L

X

X

X

3

No Operation

L

H

H

H

X

X

X

Device Deselect

H

X

X

X

X

X

X

Data Write/Output Disable

X

X

X

X

L

X

X

4

Data Mask/Output Disable

X

X

X

X

H

X

X

4

NOTES:

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).

Function

SDCE

SDRAS

SDCAS

SDWE

BWE

Notes

SDRAM COMMAND TRUTH TABLE

CLOCK FREQUENCY AND LATENCY PARAMETERS - 125MHz SDRAM

(Unit = number of clock)

Frequency

CAS

70ns

50ns

20ns

20ns

20ns

10ns

10ns

10ns

125MHz (8.0ns)

3

9

6

3

2

3

1

1

1

100MHz (10.0ns)

3

7

5

2

2

2

1

1

1

83MHz (12.0ns)

2

6

4

2

2

2

1

1

1

Latency

CLOCK FREQUENCY AND LATENCY PARAMETERS - 100MHz SDRAM

(Unit = number of clock)

Frequency

CAS

70ns

50ns

20ns

20ns

20ns

10ns

10ns

10ns

100MHz (12.0ns)

3

7

5

2

2

2

1

1

1

83MHz (12.0ns)

2

6

5

2

2

2

1

1

1

Latency

-10

-12

Parameter

Symbol

Min

Max

Min

Max

Units

Refresh Period (1,2)

—64

—

64

ms

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.

REFRESH CYCLE PARAMETERS