Cypress CY7C1383F User Manual

Page 8

Advertising
background image

CY7C1381D, CY7C1381F

CY7C1383D, CY7C1383F

Document #: 38-05544 Rev. *F

Page 8 of 29

deasserted and the IOs must be tri-stated prior to the presen-
tation of data to DQs. As a safety precaution, the data lines are
tri-stated once a write cycle is detected, regardless of the state
of OE.

Single Write Accesses Initiated by ADSC
This write access is initiated when the following conditions are
satisfied at clock rise: (1) CE

1

, CE

2

, and CE

3

[2]

are all

asserted active, (2) ADSC is asserted LOW, (3) ADSP is
deasserted HIGH, and (4) the write input signals (GW, BWE,
and BW

X

) indicate a write access. ADSC is ignored if ADSP is

active LOW.
The addresses presented are loaded into the address register
and the burst counter, the control logic, or both, and delivered
to the memory core The information presented to DQ

[A:D]

will

be written into the specified address location. Byte writes are
allowed. All IOs are tri-stated when a write is detected, even a
byte write. Since this is a common IO device, the
asynchronous OE input signal must be deasserted and the IOs
must be tri-stated prior to the presentation of data to DQ

s

. As

a safety precaution, the data lines are tri-stated once a write
cycle is detected, regardless of the state of OE.

Burst Sequences

The CY7C1381D/CY7C1383D/CY7C1381F/CY7C1383F
provides an on-chip two-bit wraparound burst counter inside
the SRAM. The burst counter is fed by A

[1:0]

, and can follow

either a linear or interleaved burst order. The burst order is
determined by the state of the MODE input. A LOW on MODE
will select a linear burst sequence. A HIGH on MODE will
select an interleaved burst order. Leaving MODE unconnected
will cause the device to default to a interleaved burst
sequence.

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. CE

1

, CE

2

, CE

3

[2]

, ADSP, and ADSC must

remain inactive for the duration of t

ZZREC

after the ZZ input

returns LOW.

Interleaved Burst Address Table

(MODE = Floating or V

DD

)

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

ZZ Mode Electrical Characteristics

Parameter

Description

Test Conditions

Min

Max

Unit

I

DDZZ

Sleep mode standby current

ZZ > V

DD

– 0.2V

80

mA

t

ZZS

Device operation to ZZ

ZZ > V

DD

– 0.2V

2t

CYC

ns

t

ZZREC

ZZ recovery time

ZZ < 0.2V

2t

CYC

ns

t

ZZI

ZZ active to sleep current

This parameter is sampled

2t

CYC

ns

t

RZZI

ZZ inactive to exit sleep current

This parameter is sampled

0

ns

[+] Feedback

Advertising