CY7C1481BV25

Document Number: 001-74847 Rev. *B

Page 8 of 21

Truth Table

The truth table for CY7C1481BV25 follows. [1, 2, 3, 4, 5]

Cycle Description

DQ

Deselected Cycle, Power Down

None

H

X

X

L

X

L

X

X

X

L–H Tri-State

Deselected Cycle, Power Down

None

L

L

X

L

L

X

X

X

X

L–H Tri-State

Deselected Cycle, Power Down

None

L

X

H

L

L

X

X

X

X

L–H Tri-State

Deselected Cycle, Power Down

None

L

L

X

L

H

L

X

X

X

L–H Tri-State

Deselected Cycle, Power Down

None

X

X

X

L

H

L

X

X

X

L–H Tri-State

Sleep Mode, Power Down

None

X

X

X

H

X

X

X

X

X

X

Tri-State

Read Cycle, Begin Burst

External

L

H

L

L

L

X

X

X

L

L–H

Q

Read Cycle, Begin Burst

External

L

H

L

L

L

X

X

X

H

L–H Tri-State

Write Cycle, Begin Burst

External

L

H

L

L

H

L

X

L

X

L–H

D

Read Cycle, Begin Burst

External

L

H

L

L

H

L

X

H

L

L–H

Q

Read Cycle, Begin Burst

External

L

H

L

L

H

L

X

H

H

L–H Tri-State

Read Cycle, Continue Burst

Next

X

X

X

L

H

H

L

H

L

L–H

Q

Read Cycle, Continue Burst

Next

X

X

X

L

H

H

L

H

H

L–H Tri-State

Read Cycle, Continue Burst

Next

H

X

X

L

X

H

L

H

L

L–H

Q

Read Cycle, Continue Burst

Next

H

X

X

L

X

H

L

H

H

L–H Tri-State

Write Cycle, Continue Burst

Next

X

X

X

L

H

H

L

L

X

L–H

D

Write Cycle, Continue Burst

Next

H

X

X

L

X

H

L

L

X

L–H

D

Read Cycle, Suspend Burst

Current

X

X

X

L

H

H

H

H

L

L–H

Q

Read Cycle, Suspend Burst

Current

X

X

X

L

H

H

H

H

H

L–H Tri-State

Read Cycle, Suspend Burst

Current

H

X

X

L

X

H

H

H

L

L–H

Q

Read Cycle, Suspend Burst

Current

H

X

X

L

X

H

H

H

H

L–H Tri-State

Write Cycle, Suspend Burst

Current

X

X

X

L

H

H

H

L

X

L–H

D

Write Cycle, Suspend Burst

Current

H

X

X

L

X

H

H

L

X

L–H

D

Notes

1. X = Do Not Care, H = Logic HIGH, L = Logic LOW.

2. WRITE = L when any one or more byte write enable signals and BWE = L or GW = L. WRITE = H when all byte write enable signals, BWE, GW = H.

3. The DQ pins are controlled by the current cycle and the OE signal. OE is asynchronous and is not sampled with the clock.

ADSP or with the assertion of ADSC. As a result, OE must be driven HIGH prior to the start of the write cycle to enable the outputs to tri-state. OE is a do not care for

the remainder of the write cycle.

5. OE is asynchronous and is not sampled with the clock rise. It is masked internally during write cycles. During a read cycle all data bits are tri-state when OE is inactive

or when the device is deselected, and all data bits behave as outputs when OE is active (LOW).