CY7C1378C
Document #: 38-05687 Rev. *F
Page 5 of 13
Burst Write Accesses
The CY7C1378C has an on-chip burst counter that allows the
user the ability to supply a single address and conduct up to
four Write operations without reasserting the address inputs.
ADV/LD must be driven LOW in order to load the initial
address, as described in the Single Write Access section
above. When ADV/LD is driven HIGH on the subsequent clock
rise, the Chip Enables (CE1, CE2, and CE3) and WE inputs are
ignored and the burst counter is incremented. The correct
BW[A:D] inputs must be driven in each cycle of the burst write
in order to write the correct bytes of data.
Sleep Mode
The ZZ input pin is an asynchronous input. Asserting ZZ
places the SRAM in a power conservation “sleep” mode. Two
clock cycles are required to enter into or exit from this “sleep”
mode. While in this mode, data integrity is guaranteed.
Accesses pending when entering the “sleep” mode are not
considered valid nor is the completion of the operation
guaranteed. The device must be deselected prior to entering
the “sleep” mode. CE1, CE2, and CE3, must remain inactive
for the duration of tZZREC after the ZZ input returns LOW.
Interleaved Burst Address Table
(MODE = Floating or VDD)
First
Address
A1, A0
Second
Address
A1, A0
Third
Address
A1, A0
Fourth
Address
A1, A0
00
01
10
11
01
00
11
10
10
11
00
01
11
10
01
00
Linear Burst Address Table
(MODE = GND)
First
Address
A1, A0
Second
Address
A1, A0
Third
Address
A1, A0
Fourth
Address
A1, A0
00
01
10
11
01
10
11
00
10
11
00
01
11
00
01
10
Cycle Description Truth Table[2, 3, 4, 5, 6, 7, 8]
Operation
Address
Used
CE
ZZ
ADV/LD
WE
BWx
OE
CEN
CLK
DQ
Deselect Cycle
None
H
L
L
X
X
X
L
L-H
Tri-State
Continue
Deselect Cycle
None
X
L
H
X
X
X
L
L-H
Tri-State
Read Cycle
(Begin Burst)
External
L
L
L
H
X
L
L
L-H
Data Out (Q)
Read Cycle
(Continue Burst)
Next
X
L
H
X
X
L
L
L-H
Data Out (Q)
NOP/Dummy Read
(Begin Burst)
External
L
L
L
H
X
H
L
L-H
Tri-State
Dummy Read
(Continue Burst)
Next
X
L
H
X
X
H
L
L-H
Tri-State
Write Cycle
(Begin Burst)
External
L
L
L
L
L
X
L
L-H
Data In (D)
Write Cycle
(Continue Burst)
Next
X
L
H
X
L
X
L
L-H
Data In (D)
NOP/WRITE ABORT
(Begin Burst)
None
L
L
L
L
H
X
L
L-H
Tri-State
WRITE ABORT
(Continue Burst)
Next
X
L
H
X
H
X
L
L-H
Tri-State
IGNORE CLOCK EDGE
(Stall)
Current
X
L
X
X
X
X
H
L-H
-
SLEEP MODE
None
X
H
X
X
X
X
X
X
Tri-State
Notes:
2. X = “Don't Care.” H = HIGH, L = LOW. CE stands for ALL Chip Enables active. BWx = 0 signifies at least one Byte Write Select is active, BWx = Valid signifies
that the desired Byte Write Selects are asserted, see Write Cycle Description table for details.
3. Write is defined by BW[A:D], and WE. See Write Cycle Descriptions table.
4. When a Write cycle is detected, all I/Os are tri-stated, even during Byte Writes.
5. The DQ pins are controlled by the current cycle and the OE signal. OE is asynchronous and is not sampled with the clock.
6. CEN = H, inserts wait states.
7. Device will power-up deselected and the I/Os in a tri-state condition, regardless of OE.
8. 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[A:D] = Three-state when
OE is inactive or when the device is deselected, and DQs = data when OE is active.