Cypress CY7C1471BV25 Computer Hardware User Manual


 
CY7C1471BV25
CY7C1473BV25, CY7C1475BV25
Document #: 001-15013 Rev. *E Page 11 of 30
Table 4. Truth Table
The truth table for CY7C1471BV25, CY7C1473BV25, and CY7C1475BV25 follows.
[1, 2, 3, 4, 5, 6, 7]
Operation
Address
Used
CE
1
CE
2
CE
3
ZZ ADV/LD WE BW
X
OE CEN CLK DQ
Deselect Cycle None H X X L L X X X L L->H Tri-State
Deselect Cycle None X X H L L X X X L L->H Tri-State
Deselect Cycle None X L X L L X X X L L->H Tri-State
Continue Deselect Cycle None X X X L H X X X L L->H Tri-State
Read Cycle
(Begin Burst)
External L H L L L H X L L L->H Data Out (Q)
Read Cycle
(Continue Burst)
Next X X X L H X X L L L->H Data Out (Q)
NOP/Dummy Read
(Begin Burst)
External L H L L L H X H L L->H Tri-State
Dummy Read
(Continue Burst)
Next X X X L H X X H L L->H Tri-State
Write Cycle
(Begin Burst)
External L H L L L L L X L L->H Data In (D)
Write Cycle
(Continue Burst)
Next X X X L H X L X L L->H Data In (D)
NOP/Write Abort
(Begin Burst)
None L H L L L L H X L L->H Tri-State
Write Abort
(Continue Burst)
Next X X X L H X H X L L->H Tri-State
Ignore Clock Edge (Stall) Current X X X L X X X X H L->H -
Sleep Mode None X X X H X X X X X X Tri-State
Notes
1. X = “Don't Care.” H = Logic HIGH, L = Logic LOW. BW
X
= L signifies at least one Byte Write Select is active, BW
X
= Valid signifies that the desired Byte Write Selects
are asserted, see “Truth Table for Read/Write” on page 12 for details.
2. Write is defined by BW
X
, and WE. See “Truth Table for Read/Write” on page 12.
3. When a write cycle is detected, all IOs are tri-stated, even during byte writes.
4. The DQs and DQP
X
pins are controlled by the current cycle and the OE signal. OE is asynchronous and is not sampled with the clock.
5. CEN
= H, inserts wait states.
6. Device powers up deselected with the IOs in a tri-state condition, regardless of OE
.
7. OE
is asynchronous and is not sampled with the clock rise. It is masked internally during write cycles. During a read cycle DQs and DQP
X
= tri-state when OE is inactive
or when the device is deselected, and DQs and DQP
X
= data when OE is active.
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