CY7C1470BV33
CY7C1472BV33, CY7C1474BV33
Document #: 001-15031 Rev. *C Page 9 of 30
access (read, write, or deselect) is latched into the Address
Register (provided the appropriate control signals are asserted).
On the next clock rise the data presented to DQ and DQP
(DQa,b,c,d/DQPa,b,c,d for CY7C1470BV33, DQa,b/DQPa,b for
CY7C1472BV33, and DQa,b,c,d,e,f,g,h/DQPa,b,c,d,e,f,g,h for
CY7C1474BV33) (or a subset for byte write operations, see
“Partial Write Cycle Description” on page11 for details) inputs is
latched into the device and the write is complete.
The data written during the Write operation is controlled by BW
(BWa,b,c,d for CY7C1470BV33, BWa,b for CY7C1472BV33, and
BWa,b,c,d,e,f,g,h for CY7C1474BV33) signals. The
CY7C1470BV33, CY7C1472BV33, and CY7C1474BV33
provides Byte Write capability that is described in “Partial Write
Cycle Description” on page11. Asserting the Write Enable input
(WE) with the selected BW input selectively writes to only the
desired bytes. Bytes not selected during a Byte Write operation
remain unaltered. A synchronous self-timed write mechanism
has been provided to simplify the write operations. Byte Write
capability has been included to greatly simplify read, modify, or
write sequences, which can be reduced to simple Byte Write
operations.
Because the CY7C1470BV33, CY7C1472BV33, and
CY7C1474BV33 are common IO devices, data must not be
driven into the device while the outputs are active. The OE can
be deasserted HIGH before presenting data to the DQ and DQP
(DQa,b,c,d/DQPa,b,c,d for CY7C1470BV33, DQa,b/DQPa,b for
CY7C1472BV33, and DQa,b,c,d,e,f,g,h/DQPa,b,c,d,e,f,g,h for
CY7C1474BV33) inputs. Doing so tri-states the output drivers.
As a safety precaution, DQ and DQP (DQa,b,c,d/DQPa,b,c,d for
CY7C1470BV33, DQa,b/DQPa,b for CY7C1472BV33, and
DQa,b,c,d,e,f,g,h/DQPa,b,c,d,e,f,g,h for CY7C1474BV33) are
automatically tri-stated during the data portion of a write cycle,
regardless of the state of OE.

Burst Write Accesses

The CY7C1470BV33, CY7C1472BV33, and CY7C1474BV33
has an on-chip burst counter that enables the user to supply a
single address and conduct up to four write operations without
reasserting the address inputs. ADV/LD must be driven LOW to
load the initial address, as described in “Single Write Accesses”
on page8. W hen 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 (BWa,b,c,d for CY7C1470BV33, BWa,b for CY7C1472V33,
and BWa,b,c,d,e,f,g,h for CY7C1474BV33) inputs must be driven
in each cycle of the burst write 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 before entering the “sleep” mode. CE1, CE2,
and CE3, must remain inactive for the duration of tZZREC after the
ZZ input returns LOW.
Table 2. Interleaved Burst Address Table
(MODE = Floating or VDD)
First
Address Second
Address Third
Address Fourth
Address
A1,A0 A1,A0 A1,A0 A1,A0
00 01 10 11
01 00 11 10
10 11 00 01
11 10 01 00
Table 3. Linear Burst Address Table (MODE = GND)
First
Address Second
Address Third
Address Fourth
Address
A1,A0 A1,A0 A1,A0 A1,A0
00 01 10 11
01 10 11 00
10 11 00 01
11 00 01 10
ZZ Mode Electrical Characteristics
Parameter Description Test Conditions Min Max Unit
IDDZZ Sleep mode standby current ZZ > VDD − 0.2V 120 mA
tZZS Device operation to ZZ ZZ > VDD − 0.2V 2tCYC ns
tZZREC ZZ recovery time ZZ < 0.2V 2tCYC ns
tZZI ZZ active to sleep current This parameter is sampled 2tCYC ns
tRZZI ZZ Inactive to exit sleep current This parameter is sampled 0 ns
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