參數(shù)資料
型號: MC68EN302PV25BT
廠商: FREESCALE SEMICONDUCTOR INC
元件分類: 微控制器/微處理器
英文描述: 4 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP144
封裝: 20 X 20 MM, 1.40 MM HEIGHT, 0.50 MM PITCH, PLASITC, LQFP-144
文件頁數(shù): 58/128頁
文件大?。?/td> 641K
代理商: MC68EN302PV25BT
MC68EN302 DRAM Control Module
3-4
MC68EN302 REFERENCE MANUAL
MOTOROLA
3.6.2 Read and Write Cycle Operation
Figure 3-1 shows two consecutive 4-clock accesses with a 2-clock precharge of RAS. RAS
is negated one clock before CAS to provide a longer precharge time between consecutive
hits in a given bank.
Figure 3-1. Consecutive Four-Clock Accesses
In some cases, a DRAM access is not possible in a 4-clock cycle. In still other cases, the
precharge time of 2 clocks is not enough for the given DRAM. Figure 3-2 shows two
consecutive 5-clock accesses, with a 3-clock RAS precharge. Note that the DRAM signals
are delayed in the second cycle with respect to the processor bus signals, allowing a longer
RAS precharge time.
S2
S3 S4 S5 S6
S1
CLOCK
S0
S7 S0 S1 S2 S3
ADDR
RAS
CAS
DRAMRW
DATA/
AS
UDS/LDS
S4 S5 S6 S7
AMUX
S0
PARITY
相關(guān)PDF資料
PDF描述
MC68302PV33C 4 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP144
SPAK302PV16VC 4 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP144
SPAK302FC25C 4 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP132
MC68EN360EM25 7 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP240
MC68EN360FE33 RISC MICROCONTROLLER, CQFP240
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC68EN360AI25L 功能描述:微處理器 - MPU QUICC ETHRN RoHS:否 制造商:Atmel 處理器系列:SAMA5D31 核心:ARM Cortex A5 數(shù)據(jù)總線寬度:32 bit 最大時鐘頻率:536 MHz 程序存儲器大小:32 KB 數(shù)據(jù) RAM 大小:128 KB 接口類型:CAN, Ethernet, LIN, SPI,TWI, UART, USB 工作電源電壓:1.8 V to 3.3 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:FBGA-324
MC68EN360AI25VL 功能描述:微處理器 - MPU QUICC ETHRN RoHS:否 制造商:Atmel 處理器系列:SAMA5D31 核心:ARM Cortex A5 數(shù)據(jù)總線寬度:32 bit 最大時鐘頻率:536 MHz 程序存儲器大小:32 KB 數(shù)據(jù) RAM 大小:128 KB 接口類型:CAN, Ethernet, LIN, SPI,TWI, UART, USB 工作電源電壓:1.8 V to 3.3 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:FBGA-324
MC68EN360AI33L 功能描述:微處理器 - MPU QUICC ETHRN RoHS:否 制造商:Atmel 處理器系列:SAMA5D31 核心:ARM Cortex A5 數(shù)據(jù)總線寬度:32 bit 最大時鐘頻率:536 MHz 程序存儲器大小:32 KB 數(shù)據(jù) RAM 大小:128 KB 接口類型:CAN, Ethernet, LIN, SPI,TWI, UART, USB 工作電源電壓:1.8 V to 3.3 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:FBGA-324
MC68EN360CAI25L 功能描述:微處理器 - MPU QUICC ETHRN RoHS:否 制造商:Atmel 處理器系列:SAMA5D31 核心:ARM Cortex A5 數(shù)據(jù)總線寬度:32 bit 最大時鐘頻率:536 MHz 程序存儲器大小:32 KB 數(shù)據(jù) RAM 大小:128 KB 接口類型:CAN, Ethernet, LIN, SPI,TWI, UART, USB 工作電源電壓:1.8 V to 3.3 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:FBGA-324
MC68EN360CEM25C 制造商: 功能描述: 制造商:undefined 功能描述: