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CY7C1381KV33 Datasheet(PDF) 7 Page - Cypress Semiconductor |
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CY7C1381KV33 Datasheet(HTML) 7 Page - Cypress Semiconductor |
7 / 34 page ![]() CY7C1381KV33/CY7C1381KVE33 CY7C1383KV33/CY7C1383KVE33 Document Number: 001-97888 Rev. *F Page 7 of 34 Pin Definitions Name I/O Description A0, A1, 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 CE1, CE2, and CE3 are sampled active. A[1:0] feed the 2-bit counter. BWA, BWB, BWC, BWD 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). 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. CE1 Input Synchronous Chip enable 1 input, active LOW. Sampled on the rising edge of CLK. Used in conjunction with CE2 and CE3 to select or deselect the device. ADSP is ignored if CE1 is HIGH. CE1 is sampled only when a new external address is loaded. CE2 Input Synchronous Chip enable 2 input, active HIGH. Sampled on the rising edge of CLK. Used in conjunction with CE1 and CE3 to select or deselect the device. CE2 is sampled only when a new external address is loaded. CE3 Input Synchronous Chip enable 3 input, active LOW. Sampled on the rising edge of CLK. Used in conjunction with CE1 and CE2 to select or deselect the device. CE3 is sampled only when a new external address is loaded. OE Input Asynchronou s 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 tristated, 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 CE1 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 Asynchronou s ZZ sleep input. This active HIGH input 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 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 DQPX are placed in a tristate condition.The outputs are automatically tristated 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. DQPX I/O Synchronous Bidirectional data parity I/O lines. Functionally, these signals are identical to DQs. During write sequences, DQPX is controlled by BWX correspondingly. |
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