參數(shù)資料
型號: SPAK302PV16VC
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
文件大小: 641K
代理商: SPAK302PV16VC
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
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
MC68360RC25 RISC MICROCONTROLLER, CPGA241
MC68EN360RC25 RISC MICROCONTROLLER, CPGA241
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SPAK56854FG120 制造商:Freescale Semiconductor 功能描述:
SPAK56857BU120 制造商:MOTOROLA 制造商全稱:Motorola, Inc 功能描述:120 MIPS Hybrid Processor
SPAK56F803BU80 制造商:Freescale Semiconductor 功能描述:
SPAK56F805FV80 制造商:Freescale Semiconductor 功能描述:
SPAKDSP303AG100 功能描述:數(shù)字信號處理器和控制器 - DSP, DSC SPAKDSP303AG100 RoHS:否 制造商:Microchip Technology 核心:dsPIC 數(shù)據(jù)總線寬度:16 bit 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:2 KB 最大時鐘頻率:40 MHz 可編程輸入/輸出端數(shù)量:35 定時器數(shù)量:3 設(shè)備每秒兆指令數(shù):50 MIPs 工作電源電壓:3.3 V 最大工作溫度:+ 85 C 封裝 / 箱體:TQFP-44 安裝風(fēng)格:SMD/SMT