поискавой системы для электроныых деталей |
|
SN74V215-15PAG датащи(PDF) 8 Page - Texas Instruments |
|
|
SN74V215-15PAG датащи(HTML) 8 Page - Texas Instruments |
8 / 43 page SN74V215, SN74V225, SN74V235, SN74V245 512 × 18, 1024 × 18, 2048 × 18, 4096 × 18 DSP-SYNC FIRST-IN, FIRST-OUT MEMORIES SCAS636E – APRIL 2000 – REVISED SEPTEMBER 2002 8 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 detailed description (continued) EMPTY FLAG/OUTPUT READY (EF/OR) This is a dual-purpose pin. In FWFT mode, the OR function is selected. OR goes low at the same time the first word written to an empty FIFO appears valid on the outputs. OR stays low after the RCLK low-to-high transition that shifts the last word from the FIFO memory to the outputs. OR goes high only with a true read (RCLK with REN low). The previous data stays at the outputs, indicating that the last word was read. Further data reads are inhibited until OR goes low again. In the standard mode, the EF function is selected. When the FIFO is empty, EF goes low, inhibiting further read operations. When EF is high, the FIFO is not empty. EF/OR is synchronous and updated on the rising edge of RCLK. PROGRAMMABLE ALMOST-FULL FLAG (PAF) PAF goes low when the FIFO reaches the almost-full condition. In FWFT mode, if no reads are performed, PAF goes low after 513 – m for the SN74V215, 1025 for the SN74V225, 2049 for the SN74V235, and 4097 for the SN74V245. Default values for m are in Table 3 and Table 4. In standard mode, if no reads are performed after reset (RS), PAF goes low after (512 – m) writes for the SN74V215, (1024 – m) writes for the SN74V225, (2048 – m) writes for the SN74V235, and (4096 – m) writes for the SN74V245. The offset m is defined in the full offset register. If asynchronous PAF configuration is selected, PAF is asserted low on the low-to-high transition of WCLK. PAF is reset to high on the low-to-high transition of RCLK. If synchronous PAF configuration is selected (see Table 5), PAF is updated on the rising edge of WCLK. PROGRAMMABLE ALMOST-EMPTY FLAG (PAE) PAE goes low when the FIFO reaches the almost-empty condition. In FWFT mode, PAE goes low when there are n + 1 words, or fewer, in the FIFO. In standard mode, PAE goes low when there are n words or fewer in the FIFO. The offset n is defined as the empty offset. The default values for n are noted in Table 3 and Table 4. If there is no empty offset specified, PAE is low when the device is 63 away from completely empty for SN74V215, and 127 away from completely empty for SN74V225, SN74V235, and SN74V245. If asynchronous PAE configuration is selected, PAE is asserted low on the low-to-high transition of the read clock (RCLK). PAE is reset to high on the low-to-high transition of the write clock (WCLK). If synchronous PAE configuration is selected (see Table 5), PAE is updated on the rising edge of RCLK. WRITE EXPANSION OUT/HALF-FULL FLAG (WXO/HF) This is a dual-purpose output. In the single-device and width-expansion mode, when write expansion in (WXI) and/or read expansion in (RXI) are grounded, this output acts as an indication of a half-full memory. After one-half of the memory is filled, and at the low-to-high transition of the next write cycle, the half-full flag (HF) goes low and remains 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. HF is then reset to high by the low-to-high transition of the read clock (RCLK). HF is asynchronous. In the daisy-chain depth-expansion mode, WXI is connected to WXO of the previous device. This output acts as a signal to the next device in the daisy chain by providing a pulse when the previous device writes to the last location of memory. READ EXPANSION OUT (RXO) In the daisy-chain depth-expansion configuration, read expansion in (RXI) is connected to read expansion out (RXO) of the previous device. This output acts as a signal to the next device in the daisy chain by providing a pulse when the previous device reads from the last location of memory. |
Аналогичный номер детали - SN74V215-15PAG |
|
Аналогичное описание - SN74V215-15PAG |
|
|
ссылки URL |
Конфиденциальность |
ALLDATASHEETRU.COM |
Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | обмен ссыками | поиск по производителю 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 |