Cypress CY7C1361C Computer Hardware User Manual


 
CY7C1361C
CY7C1363C
Document #: 38-05541 Rev. *F Page 7 of 31
Pin Definitions
Name I/O Description
A
0
, A
1
, A Input-
Synchronous
Address Inputs used to select one of the address locations. Sampled at the rising
edge of the CLK if ADSP
or ADSC is active LOW, and CE
1
,
CE
2
, and
CE
3
[2]
are sampled
active. A
[1:0]
feed the 2-bit counter.
BW
A
,BW
B
BW
C
,BW
D
Input-
Synchronous
Byte Write Select Inputs, active LOW. Qualified with BWE to conduct byte writes to the
SRAM. Sampled on the rising edge of CLK.
GW Input-
Synchronous
Global Write Enable Input, active LOW. When asserted LOW on the rising edge of CLK, a
global write is conducted (ALL bytes are written, regardless of the values on BW
X
and BWE).
CLK Input-
Clock
Clock Input. Used to capture all synchronous inputs to the device. Also used to increment
the burst counter when ADV is asserted LOW, during a burst operation.
CE
1
Input-
Synchronous
Chip Enable 1 Input, active LOW. Sampled on the rising edge of CLK. Used in
conjunction with CE
2
and CE
3
[2]
to select/deselect the device. ADSP is ignored if CE
1
is
HIGH. CE
1
is sampled only when a new external address is loaded.
CE
2
Input-
Synchronous
Chip Enable 2 Input, active HIGH. Sampled on the rising edge of CLK. Used in
conjunction with CE
1
and CE
3
[2]
to select/deselect the device. CE
2
is sampled only when
a new external address is loaded.
CE
3
[2]
Input-
Synchronous
Chip Enable 3 Input, active LOW. Sampled on the rising edge of CLK. Used in
conjunction with CE
1
and CE
2
to select/deselect the device.CE
3
is sampled only when a
new external address is loaded.
OE Input-
Asynchronous
Output Enable, asynchronous input, active LOW. Controls the direction of the I/O pins.
When LOW, the I/O pins behave as outputs. When deasserted HIGH, I/O pins are
tri-stated, and act as input data pins. OE is masked during the first clock of a read cycle
when emerging from a deselected state.
ADV Input-
Synchronous
Advance Input signal, sampled on the rising edge of CLK. When asserted, it automat-
ically increments the address in a burst cycle.
ADSP Input-
Synchronous
Address Strobe from Processor, sampled on the rising edge of CLK, active LOW.
When asserted LOW, addresses presented to the device are captured in the address
registers. A
[1:0]
are also loaded into the burst counter. When ADSP and ADSC are both
asserted, only ADSP
is recognized. ASDP is ignored when
CE
1
is deasserted HIGH.
ADSC
Input-
Synchronous
Address Strobe from Controller, sampled on the rising edge of CLK, active LOW.
When asserted LOW, addresses presented to the device are captured in the address
registers. A
[1:0]
are also loaded into the burst counter. When ADSP and ADSC are both
asserted, only ADSP
is recognized.
BWE
Input-
Synchronous
Byte Write Enable Input, active LOW. Sampled on the rising edge of CLK. This signal
must be asserted LOW to conduct a byte write.
ZZ Input-
Asynchronous
ZZ “sleep” Input, active HIGH. When asserted HIGH places the device in a
non-time-critical “sleep” condition with data integrity preserved. For normal operation,
this pin has to be LOW or left floating. ZZ pin has an internal pull-down.
DQ
s
I/O-
Synchronous
Bidirectional Data I/O lines. As inputs, they feed into an on-chip data register that is
triggered by the rising edge of CLK. As outputs, they deliver the data contained in the
memory location specified by the addresses presented during the previous clock rise of
the read cycle. The direction of the pins is controlled by OE
. When OE is asserted LOW,
the pins behave as outputs. When HIGH, DQ
s
and DQP
X
are placed in a tri-state
condition.The outputs are automatically tri-stated during the data portion of a write
sequence, during the first clock when emerging from a deselected state, and when the
device is deselected, regardless of the state of OE
.
DQP
X
I/O-
Synchronous
Bidirectional Data Parity I/O Lines. Functionally, these signals are identical to DQ
s
.
During write sequences, DQP
X
is controlled by BW
X
correspondingly.
MODE Input-
Static
Selects Burst Order. When tied to GND selects linear burst sequence. When tied to V
DD
or left floating selects interleaved burst sequence. This is a strap pin and should remain
static during device operation. Mode Pin has an internal pull-up.
V
DD
Power Supply Power supply inputs to the core of the device.
V
DDQ
I/O Power Supply Power supply for the I/O circuitry.
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