 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
L8C201PC12 Datasheet(PDF) 2 Page - LOGIC Devices Incorporated |
|
||||||||||||||||||||||||||||||
L8C201PC12 Datasheet(HTML) 2 Page - LOGIC Devices Incorporated |
|
|
2 / 22 page  DEVICES INCORPORATED L8C201/202/203/204 512/1K/2K/4K x 9-bit Asynchronous FIFO 2 FIFO Products 03/04/99–LDS.8C201/2/3/4-H “final” read cycle but inhibiting further read operations with the data outputs remaining in a high imped- ance state. Once a valid write operat- ing has been accomplished, the Empty Flag (EF) will go HIGH after tWHEH and a valid read can then begin. When the FIFO is empty, the internal read pointer is blocked from R so external changes in R will not affect the FIFO. FL/RT — First Load/Retransmit This is a dual-purpose input. In the Depth Expansion Mode, this pin is grounded to indicate that it is the first loaded (see Operating Modes). In the Single Device Mode, this pin acts as the retransmit input. The Single Device Mode is initiated by grounding the Expansion In (XI). The FIFOs can be made to retransmit data when the Retransmit Enable control (RT) input is pulsed LOW. A retransmit operation will set the internal read pointer to the first location and will not affect the write pointer. Read Enable (R) and Write Enable (W) must be in the HIGH state during retransmit. This feature is useful when less than the full memory has been written between resets. Retransmit will affect the Half-Full Flag (HF), depend- ing on the relative locations of the read and write pointers. The retransmit feature is not compatible with the Depth Expansion Mode. XI — Expansion In This input is a dual-purpose pin. Expansion In (XI) is grounded to indicate an operation in the single device mode. Expansion In (XI) is connected to Expansion Out (XO) of the previous device in the Depth Expansion or Daisy Chain Mode. D8-0 — Data Input Data input signals for 9-bit wide data. Data has setup and hold time require- ments with respect to the rising edge of W. SIGNAL DEFINITIONS Inputs RS — Reset Reset is accomplished whenever the Reset (RS) input is taken to a LOW state. During reset, both internal read and write pointers are set to the first location. A reset is required after power-up before a write operation can take place. Both the Read Enable (R) and Write Enable (W) inputs must be in the HIGH state during the window shown (i.e., tWHSH before the rising edge of RS) and should not change until tSHWL after the rising edge of RS. Hall-Full Flag (HF) will be reset to high after Reset (RS). W — Write Enable A write cycle is initiated on the falling edge of this input if the Full Flag (FF) is not set. Data setup and hold time must be adhered to with respect to the rising edge of the Write Enable (W). Data is stored in the RAM array sequentially and independently of any on-going read operation. To prevent data overflow, the Full Flag (FF) will go LOW, inhibiting further write operations. Upon the completion of a valid read operation, the Full Flag (FF) will go HIGH after t RHFH, allowing a valid write to begin. When the FIFO is full, the internal write pointer is blocked from W, so external changes in W will not affect the FIFO when it is full. R — Read Enable A read cycle is initiated on the falling edge of the Read Enable (R) provided the Empty Flag (EF) is not set. The data is accessed on a First-In/First- Out basis, independent of any ongo- ing write operation. After Read Enable (R) goes HIGH, the Data Outputs (D8-0) will return to a high impedance condition until the next read operation. When all the data has been read from the FIFO, the Empty Flag (EF) will go LOW, allowing the Outputs FF — Full Flag The Full Flag (FF) will go LOW, inhibiting further write operations, indicating that the device is full. If the read pointer is not moved after Reset (RS), the Full Flag (FF) will go LOW after 512 writes for the L8C201, 1024 writes for the L8C202, 2048 writes for the L8C203, and 4096 writes for the L8C204 . EF — Empty Flag The Empty Flag (EF) will go LOW, inhibiting further read operations, when the read pointer is equal to the write pointer, indicating that the device is empty. XO/HF — Expansion Out/Half-Full Flag This is a dual-purpose output. In the Single Device Mode, when Expansion In (XI) is grounded, this output acts as an indication of a half-full memory. After half of the memory is filled and at the falling edge of the next write operation, the Half-Full Flag (HF) will be set to LOW and will remain set until the difference between the write pointer and read pointer is less than or equal to one-half of the total memory of the device. The Half-Full Flag (HF) is then deasserted by the rising edge of the read operation. In the Depth Expansion Mode, Expansion In (XI) is connected to Expansion Out (XO) of the previous device. This output acts as a signal to the next device in the daisy chain by providing a pulse to the next device when the previous device reaches the last location of memory. Q8-0 — Data Output Data outputs for 9-bit wide data. This data is in a high impedance condition whenever Read Enable (R) is in a HIGH state or the device is empty. |
Similar Part No. - L8C201PC12 |
|
Similar Description - L8C201PC12 |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
