IDT7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
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. Semaphores 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 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 continuously without any wait states.
L PORT
SEMAPHORE
REQUEST FLIP FLOP
Military, Industrial and Commercial Temperature Ranges
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
Figure 4. IDT7024 Semaphore Logic
20
6.42
WRITE
SEMAPHORE
READ
2740 drw 20
,
相关PDF资料
IDT7025L55G IC SRAM 128KBIT 55NS 84PGA
IDT70261L20PFI IC SRAM 256KBIT 20NS 100TQFP
IDT7026L20G IC SRAM 256KBIT 20NS 84PGA
IDT7027L25G IC SRAM 512KBIT 25NS 108PGA
IDT7028L20PFI IC SRAM 1MBIT 20NS 100TQFP
IDT7034L20PFI IC SRAM 72KBIT 20NS 100TQFP
IDT7035L20PFI IC SRAM 144KBIT 20NS 100TQFP
IDT7037L20PFI IC SRAM 576KBIT 20NS 100TQFP
相关代理商/技术参数
IDT7024L55GB 制造商:Integrated Device Technology Inc 功能描述:IC SRAM 64KBIT 55NS 84PGA
IDT7024L55J 功能描述:IC SRAM 64KBIT 55NS 84PLCC 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
IDT7024L55J8 功能描述:IC SRAM 64KBIT 55NS 84PLCC RoHS:否 类别:集成电路 (IC) >> 存储器 系列:- 标准包装:72 系列:- 格式 - 存储器:RAM 存储器类型:SRAM - 同步 存储容量:9M(256K x 36) 速度:75ns 接口:并联 电源电压:3.135 V ~ 3.465 V 工作温度:-40°C ~ 85°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:71V67703S75PFGI
IDT7024L55PF 功能描述:IC SRAM 64KBIT 55NS 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
IDT7024L55PF8 功能描述:IC SRAM 64KBIT 55NS 100TQFP RoHS:否 类别:集成电路 (IC) >> 存储器 系列:- 标准包装:72 系列:- 格式 - 存储器:RAM 存储器类型:SRAM - 同步 存储容量:9M(256K x 36) 速度:75ns 接口:并联 电源电压:3.135 V ~ 3.465 V 工作温度:-40°C ~ 85°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:71V67703S75PFGI
IDT7024L70GB 制造商:Integrated Device Technology Inc 功能描述:IC SRAM 64KBIT 70NS 84PGA
IDT7024S15J 功能描述:IC SRAM 64KBIT 15NS 84PLCC 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
IDT7024S15J8 功能描述:IC SRAM 64KBIT 15NS 84PLCC 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