データシートサーチシステム |
|
SN74ACT2227DW データシート(PDF) 1 Page - Texas Instruments |
|
|
SN74ACT2227DW データシート(HTML) 1 Page - Texas Instruments |
1 / 13 page SN74ACT2227, SN74ACT2229 DUAL 64 × 1, DUAL 256 × 1 FIRST-IN, FIRST-OUT MEMORIES SCAS220C – JUNE 1992 – REVISED OCTOBER 1997 1 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 D Dual Independent FIFOs Organized as: 64 Words by 1 Bit Each – SN74ACT2227 256 Words by 1 Bit Each – SN74ACT2229 D Free-Running Read and Write Clocks Can Be Asynchronous or Coincident on Each FIFO D Input-Ready Flags Synchronized to Write Clocks D Output-Ready Flags Synchronized to Read Clocks D Half-Full and Almost-Full/Almost-Empty Flags D Support Clock Frequencies up to 60 MHz D Access Times of 9 ns D 3-State Data Outputs D Low-Power Advanced CMOS Technology D Packaged in 28-Pin SOIC Package description The SN74ACT2227 and SN74ACT2229 are dual FIFOs suited for a wide range of serial-data buffering applications including elastic stores for frequencies up to OC-1 telecommunication rates. Each FIFO on the chip is arranged as 64 × 1 (SN74ACT2227) or 256 × 1 (SN74ACT2229) and has control signals and status flags for independent operation. Output flags for each FIFO include input ready (1IR or 2IR), output ready (1OR or 2OR), half full (1HF or 2HF), and almost full/almost empty (1AF/AE or 2AF/AE). Serial data is written into a FIFO on the low-to-high transition of the write-clock (1WRTCLK or 2WRTCLK) input when the write-enable (1WRTEN or 2WRTEN) input and input-ready flag (1IR or 2IR) output are both high. Serial data is read from a FIFO on the low-to-high transition of the read-clock (1RDCLK or 2RDCLK) input when the read-enable (1RDEN or 2RDEN) input and output-ready flag (1OR or 2OR) output are both high. The read and write clocks of a FIFO can be asynchronous to one another. A FIFO data output (1Q or 2Q) is in the high-impedance state when its output-enable (1OE or 2OE) input is low. Each input-ready flag (1IR or 2IR) is synchronized by two flip-flop stages to its write clock (1WRTCLK or 2WRTCLK), and each output-ready flag (1OR or 2OR) is synchronized by three flip-flop stages to its read clock (1RDCLK or 2RDCLK). This multistage synchronization ensures reliable flag-output states when data is written and read asynchronously. A half-full flag (1HF or 2HF) is high when the number of bits stored in its FIFO is greater than or equal to half the depth of the FIFO. An almost-full/almost-empty flag (1AF/AE or 2AF/AE) is high when eight or fewer bits are stored in its FIFO and when eight or fewer empty locations are left in the FIFO. A bit present on the data output is not stored in the FIFO. The SN74ACT2227 and SN74ACT2229 are characterized for operation from – 40 °C to 85°C. For more information on this device family, see the application report FIFOs With a Word Width of One Bit (literature number SCAA006). Copyright © 1997, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 1HF 1AF/AE 1WRTCLK 1WRTEN 1IR 1D GND GND 1RESET 2Q 2OR 2RDEN 2RDCLK 2OE 1OE 1RDCLK 1RDEN 1OR 1Q 2RESET VCC VCC 2D 2IR 2WRTEN 2WRTCLK 2AF/AE 2HF DW PACKAGE (TOP VIEW) |
同様の部品番号 - SN74ACT2227DW |
|
同様の説明 - SN74ACT2227DW |
|
|
リンク URL |
プライバシーポリシー |
ALLDATASHEET.JP |
ALLDATASHEETはお客様のビジネスに役立ちますか? [ DONATE ] |
Alldatasheetは | 広告 | お問い合わせ | プライバシーポリシー | リンク交換 | メーカーリスト 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 |