参数资料
型号: IDT72261LA20PF8
厂商: IDT, Integrated Device Technology Inc
文件页数: 4/27页
文件大小: 0K
描述: IC FIFO 8192X18 LP 20NS 64QFP
标准包装: 750
系列: 7200
功能: 同步
存储容量: 144K(8K x 18)
数据速率: 50MHz
访问时间: 20ns
电源电压: 4.5 V ~ 5.5 V
工作温度: 0°C ~ 70°C
安装类型: 表面贴装
封装/外壳: 64-LQFP
供应商设备封装: 64-TQFP(14x14)
包装: 带卷 (TR)
其它名称: 72261LA20PF8
12
COMMERCIALANDINDUSTRIAL
TEMPERATURERANGES
IDT72261LA/72271LA SuperSync FIFO
16,384 x 9 and 32,768 x 9
SIGNAL DESCRIPTION
INPUTS:
DATA IN (D0 - D8)
Data inputs for 9-bit wide data.
CONTROLS:
MASTER RESET (MRS)
A Master Reset is accomplished whenever the MRS input is taken to a
LOW state. This operation sets the internal read and write pointers to the
first location of the RAM array. PAE will go LOW, PAF will go HIGH, and
HF will go HIGH.
If FWFT is LOW during Master Reset then the IDT Standard mode,
along with EF and FF are selected. EF will go LOW and FF will go HIGH.
If FWFT is HIGH, then the First Word Fall Through mode (FWFT), along
with IR and OR, are selected. OR will go HIGH and IR will go LOW.
If LD is LOW during Master Reset, then PAE is assigned a threshold 127
words from the empty boundary and PAF is assigned a threshold 127
words from the full boundary; 127 words corresponds to an offset value of
07FH. Following Master Reset, parallel loading of the offsets is permitted,
but not serial loading.
If LD is HIGH during Master Reset, then PAE is assigned a threshold
1,023 words from the empty boundary and PAF is assigned a threshold
1,023 words from the full boundary; 1,023 words corresponds to an offset
value of 3FFH. Following Master Reset, serial loading of the offsets is
permitted, but not parallel loading.
Parallel reading of the registers is always permitted. (See section
describing the LD pin for further details.)
During a Master Reset, the output register is initialized to all zeroes. A
Master Reset is required after power up, before a write operation can take
place. MRS is asynchronous.
See Figure 5, Master Reset Timing, for the relevant timing diagram.
PARTIAL RESET (PRS)
A Partial Reset is accomplished whenever the PRS input is taken to a
LOW state. As in the case of the Master Reset, the internal read and write
pointers are set to the first location of the RAM array, PAE goes LOW, PAF
goes HIGH, and HF goes HIGH.
Whichever mode is active at the time of Partial Reset, IDT Standard mode
or First Word Fall Through, that mode will remain selected. If the IDT Standard
mode is active, then FF will go HIGH and EF will go LOW. If the First Word
Fall Through mode is active, then OR will go HIGH, and IR will go LOW.
Following Partial Reset, all values held in the offset registers remain
unchanged. The programming method (parallel or serial) currently active
at the time of Partial Reset is also retained. The output register is initialized
to all zeroes. PRS is asynchronous.
A Partial Reset is useful for resetting the device during the course of
operation, when reprogramming partial flag offset settings may not be
convenient.
See Figure 6, Partial Reset Timing, for the relevant timing diagram.
RETRANSMIT (RT)
The Retransmit operation allows data that has already been read to be
accessed again. There are two stages: first, a setup procedure that resets
the read pointer to the first location of memory, then the actual retransmit,
which consists of reading out the memory contents, starting at the
beginning of the memory.
Retransmit setup is initiated by holding RT LOW during a rising RCLK
edge. REN and WEN must be HIGH before bringing RT LOW.
If IDT Standard mode is selected, the FIFO will mark the beginning of the
Retransmit setup by setting EF LOW. The change in level will only be
noticeable if EF was HIGH before setup. During this period, the internal
read pointer is initialized to the first location of the RAM array.
When EF goes HIGH, Retransmit setup is complete and read operations
may begin starting with the first location in memory. Since IDT Standard
mode is selected, every word read including the first word following
Retransmit setup requires a LOW on REN to enable the rising edge of
RCLK. See Figure 11, Retransmit Timing (IDT Standard Mode), for the
relevant timing diagram.
If FWFT mode is selected, the FIFO will mark the beginning of the
Retransmit setup by setting OR HIGH. During this period, the internal read
pointer is set to the first location of the RAM array.
When OR goes LOW, Retransmit setup is complete; at the same time,
the contents of the first location appear on the outputs. Since FWFT mode
is selected, the first word appears on the outputs, no LOW on REN is
necessary. Reading all subsequent words requires a LOW on REN to
enable the rising edge of RCLK. See Figure 12, Retransmit Timing (FWFT
Mode), for the relevant timing diagram.
FIRST WORD FALL THROUGH/SERIAL IN (FWFT/SI)
This is a dual purpose pin. During Master Reset, the state of the FWFT/
SI input determines whether the device will operate in IDT Standard mode
or First Word Fall Through (FWFT) mode.
If, at the time of Master Reset, FWFT/SI is LOW, then IDT Standard
mode will be selected. This mode uses the Empty Flag (EF) to indicate
whether or not there are any words present in the FIFO memory. It also
uses the Full Flag function (FF) to indicate whether or not the FIFO memory
has any free space for writing. In IDT Standard mode, every word read
from the FIFO, including the first, must be requested using the Read
Enable (REN) and RCLK.
If, at the time of Master Reset, FWFT/SI is HIGH, then FWFT mode will be
selected. This mode uses Output Ready (OR) to indicate whether or not there
is valid data at the data outputs (Qn). It also uses Input Ready (IR) to indicate
whether or not the FIFO memory has any free space for writing. In the FWFT
mode, the first word written to an empty FIFO goes directly to Qn after three
RCLK rising edges, REN = LOW is not necessary. Subsequent words must
be accessed using the Read Enable (REN) and RCLK.
After Master Reset, FWFT/SI acts as a serial input for loading PAE and
PAF offsets into the programmable registers. The serial input function can
only be used when the serial loading method has been selected during
Master Reset. Serial programming using the FWFT/SI pin functions the
same way in both IDT Standard and FWFT modes.
WRITE CLOCK (WCLK)
A write cycle is initiated on the rising edge of the WCLK input. Data setup
and hold times must be met with respect to the LOW-to-HIGH transition of
the WCLK. It is permissible to stop the WCLK. Note that while WCLK is idle,
the FF/IR, PAF and HF flags will not be updated. (Note that WCLK is only
capable of updating HF flag to LOW.) The Write and Read Clocks can
either be independent or coincident.
相关PDF资料
PDF描述
MS27466E15F15P CONN RCPT 15POS WALL MT W/PINS
VI-262-IW-F3 CONVERTER MOD DC/DC 15V 100W
VI-262-IW-F2 CONVERTER MOD DC/DC 15V 100W
VI-262-IW-F1 CONVERTER MOD DC/DC 15V 100W
VI-261-IX-B1 CONVERTER MOD DC/DC 12V 75W
相关代理商/技术参数
参数描述
IDT72261LA20PFI 功能描述:IC FIFO 8192X18 LP 20NS 64QFP RoHS:否 类别:集成电路 (IC) >> 逻辑 - FIFO 系列:7200 标准包装:90 系列:7200 功能:同步 存储容量:288K(16K x 18) 数据速率:100MHz 访问时间:10ns 电源电压:4.5 V ~ 5.5 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:64-LQFP 供应商设备封装:64-TQFP(14x14) 包装:托盘 其它名称:72271LA10PF
IDT72261LA20PFI8 功能描述:IC FIFO 8192X18 LP 20NS 64QFP RoHS:否 类别:集成电路 (IC) >> 逻辑 - FIFO 系列:7200 标准包装:90 系列:7200 功能:同步 存储容量:288K(16K x 18) 数据速率:100MHz 访问时间:10ns 电源电压:4.5 V ~ 5.5 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:64-LQFP 供应商设备封装:64-TQFP(14x14) 包装:托盘 其它名称:72271LA10PF
IDT72261LA20TF 功能描述:IC FIFO 8192X18 LP 20NS 64QFP RoHS:否 类别:集成电路 (IC) >> 逻辑 - FIFO 系列:7200 标准包装:90 系列:7200 功能:同步 存储容量:288K(16K x 18) 数据速率:100MHz 访问时间:10ns 电源电压:4.5 V ~ 5.5 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:64-LQFP 供应商设备封装:64-TQFP(14x14) 包装:托盘 其它名称:72271LA10PF
IDT72261LA20TF8 功能描述:IC FIFO 8192X18 LP 20NS 64QFP RoHS:否 类别:集成电路 (IC) >> 逻辑 - FIFO 系列:7200 标准包装:90 系列:7200 功能:同步 存储容量:288K(16K x 18) 数据速率:100MHz 访问时间:10ns 电源电压:4.5 V ~ 5.5 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:64-LQFP 供应商设备封装:64-TQFP(14x14) 包装:托盘 其它名称:72271LA10PF
IDT72261LA20TFI 功能描述:IC FIFO 8192X18 LP 20NS 64QFP RoHS:否 类别:集成电路 (IC) >> 逻辑 - FIFO 系列:7200 标准包装:90 系列:7200 功能:同步 存储容量:288K(16K x 18) 数据速率:100MHz 访问时间:10ns 电源电压:4.5 V ~ 5.5 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:64-LQFP 供应商设备封装:64-TQFP(14x14) 包装:托盘 其它名称:72271LA10PF