Cypress CY7C1346H Computer Hardware User Manual


 
CY7C1346H
Document #: 38-05672 Rev. *B Page 5 of 16
Burst Sequences
The CY7C1346H provides a two-bit wraparound counter, fed
by A
1
, A
0
, that implements either an interleaved or linear burst
sequence. The interleaved burst sequence is designed specif-
ically to support Intel Pentium applications. The linear burst
sequence is designed to support processors that follow a
linear burst sequence. The burst sequence is user selectable
through the MODE input.
Asserting ADV
LOW at clock rise will automatically increment
the burst counter to the next address in the burst sequence.
Both Read and Write burst operations are supported.
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
, 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
A
1
, A
0
Second
Address
A
1
, A
0
Third
Address
A
1
, A
0
Fourth
Address
A
1
, A
0
00 01 10 11
01 00 11 10
10 11 00 01
11 10 01 00
Linear Burst Address Table (MODE = GND)
First
Address
A
1
, A
0
Second
Address
A
1
, A
0
Third
Address
A
1
, A
0
Fourth
Address
A
1
, A
0
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 40 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
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