参数资料
型号: IDT7034S20PF
厂商: IDT, Integrated Device Technology Inc
文件页数: 18/19页
文件大小: 0K
描述: IC SRAM 72KBIT 20NS 100TQFP
标准包装: 3
格式 - 存储器: RAM
存储器类型: SRAM - 双端口,异步
存储容量: 72K(4K x 18)
速度: 20ns
接口: 并联
电源电压: 4.5 V ~ 5.5 V
工作温度: 0°C ~ 70°C
封装/外壳: 100-LQFP
供应商设备封装: 100-TQFP(14x14)
包装: 托盘
其它名称: 7034S20PF
IDT7034S/L
High-Speed 4K x 18 Dual-Port Static RAM
lower 2K. Meanwhile the right processor was attempting to gain control
of the resource after the left processor, it would read back a one in
response to the zero it had attempted to write into Semaphore 0. At this
point, the software could choose to try and gain control of the second
2K section by writing, then reading a zero into Semaphore 1. If it
succeeded in gaining control, it would lock out the left side.
Once the left side was finished with its task, it would write a one to
Semaphore 0 and may then try to gain access to Semaphore 1. If
Semaphore 1 was still occupied by the right side, the left side could
undo its semaphore request and perform other tasks until it was able
to write, then read a zero into Semaphore 1. If the right processor
performs a similar task with Semaphore 0, this protocol would allow the
two processors to swap 2K blocks of Dual-Port RAM with each other.
The blocks do not have to be any particular size and can even be
variable, depending upon the complexity of the software using the
semaphore flags. All eight semaphores could be used to divide the
Dual-Port RAM or other shared resources into eight parts. Sema-
phores can even be assigned different meanings on different sides
rather than being given a common meaning as was shown in the
example above.
Semaphores are a useful form of arbitration in systems like disk
interfaces where the CPU must be locked out of a section of memory
L PORT
SEMAPHORE
REQUEST FLIP FLOP
Industrial and Commercial Temperature Ranges
during a transfer and the I/O device cannot tolerate any wait states.
With the use of semaphores, once the two devices has determined
which memory area was “off-limits” to the CPU, both the CPU and the
I/O devices could access their assigned portions of memory continu-
ously without any wait states.
Semaphores are also useful in applications where no memory
“WAIT” state is available on one or both sides. Once a semaphore
handshake has been performed, both processors can access their
assigned RAM segments at full speed.
Another application is in the area of complex data structures. In this
case, block arbitration is very important. For this application one
processor may be responsible for building and updating a data
structure. The other processor then reads and interprets that data
structure. If the interpreting processor reads an incomplete data
structure, a major error condition may exist. Therefore, some sort of
arbitration must be used between the two different processors. The
building processor arbitrates for the block, locks it and then is able to
go in and update the data structure. When the update is completed,
the data structure block is released. This allows the interpreting
processor to come back and read the complete data structure, thereby
guaranteeing a consistent data structure.
R PORT
SEMAPHORE
REQUEST FLIP FLOP
D 0
D
Q
Q
D
D 0
WRITE
SEMAPHORE
READ
WRITE
SEMAPHORE
READ
Figure 4. IDT7034 Semaphore Logic
18
4089 drw 18
.
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IDT7035L15PF 功能描述:IC SRAM 144KBIT 15NS 100TQFP RoHS:否 类别:集成电路 (IC) >> 存储器 系列:- 标准包装:1,000 系列:- 格式 - 存储器:RAM 存储器类型:SRAM - 双端口,同步 存储容量:1.125M(32K x 36) 速度:5ns 接口:并联 电源电压:3.15 V ~ 3.45 V 工作温度:-40°C ~ 85°C 封装/外壳:256-LBGA 供应商设备封装:256-CABGA(17x17) 包装:带卷 (TR) 其它名称:70V3579S5BCI8
IDT7035L15PF8 功能描述:IC SRAM 144KBIT 15NS 100TQFP RoHS:否 类别:集成电路 (IC) >> 存储器 系列:- 标准包装:45 系列:- 格式 - 存储器:RAM 存储器类型:SRAM - 双端口,异步 存储容量:128K(8K x 16) 速度:15ns 接口:并联 电源电压:3 V ~ 3.6 V 工作温度:0°C ~ 70°C 封装/外壳:100-LQFP 供应商设备封装:100-TQFP(14x14) 包装:托盘 其它名称:70V25S15PF
IDT7035L20PF 功能描述:IC SRAM 144KBIT 20NS 100TQFP RoHS:否 类别:集成电路 (IC) >> 存储器 系列:- 标准包装:45 系列:- 格式 - 存储器:RAM 存储器类型:SRAM - 双端口,异步 存储容量:128K(8K x 16) 速度:15ns 接口:并联 电源电压:3 V ~ 3.6 V 工作温度:0°C ~ 70°C 封装/外壳:100-LQFP 供应商设备封装:100-TQFP(14x14) 包装:托盘 其它名称:70V25S15PF
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