Cypress CY7C1217H - Manual (Page 4)

CY7C1217H
Document #: 38-05670 Rev. *B Page 4 of 16
Pin Descriptions
Name I/O Description
A0, A1, A Input-
Synchronous
Address Inputs used to select one of the 32K 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
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
[A:D]
and
BWE).
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.
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
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
to select/deselect the device. CE
2
is sampled only when a new external
address is loaded.
CE
3
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 automatically
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.
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.
DQs
DQP
A,
DQP
B
DQP
C,
DQP
D
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, DQs and DQP
[A:D]
are placed in a tri-state condition.
V
DD
Power Supply Power supply inputs to the core of the device.
V
SS
Ground Ground for the core of the device.
V
DDQ
I/O Power Supply Power supply for the I/O circuitry.
V
SSQ
I/O Ground Ground for the I/O circuitry.
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.
NC No Connects. Not Internally connected to the die. 2M, 4M, 9M, 18M, 72M, 144M, 288M,
576M and 1G are address expansion pins and are not internally connected to the die.
[+] Feedback