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參數資料
| 型號： | DS89C440-MNL |
| 英文描述： | Ultra-High-Speed Flash Microcontrollers |
| 中文描述： | 超高速閃存微控制器 |
| 文件頁數： | 26/48頁 |
| 文件大?。?/td> | 656K |
| 代理商： | DS89C440-MNL |
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DS89C430/DS89C440/DS89C450 Ultra-High-Speed Flash Microcontrollers
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External Memory
The DS89C430 executes external memory cycles for code fetches and read/writes of external program and data
memory. A nonpage external memory cycle is four times slower than the internal memory cycles (i.e., an external
memory cycle contains four system clocks). However, a page mode external memory cycle can be completed in
one, two, or four system clocks for a page hit and two, four, or eight system clocks for a page miss, depending on
user selection. The DS89C430 also supports a second page mode operation with a different external bus structure
that provides for fast external code fetches but uses four system clock cycles for data memory access.
External Program Memory Interface (Nonpage Mode)
Figure 7
shows the timing relationship for internal and external code fetches when CD1 and CD0 are set to 10b,
assuming the microcontroller is in nonpage mode for external fetches. Note that an external program fetch takes
four system clocks, and an internal program fetch requires only one system clock.
As illustrated in
Figure 7
, ALE is deasserted when executing an internal memory fetch. The DS89C430 provides a
programmable user option to turn on ALE during internal program memory operation. ALE is automatically enabled
for code fetch externally, independent of the setting of this option.
PSEN
is only asserted for external code fetches, and is inactive during internal execution.
Figure 7. External Program Memory Access (Nonpage Mode, CD1:CD0 = 10)
Internal Memory Cycles
C1
C2
C3
C4 C1 C2 C3 C4
XTAL1
ALE
Port 0
Port 2
PSEN
External Memory Cycle
External Memory Cycle
MSB Add MSB Add
LSB Add Data LSB Add Data
相關PDF資料 |
PDF描述 |
|---|---|
| DS89C440-QNL | Ultra-High-Speed Flash Microcontrollers |
| DS89C450-ENL | Ultra-High-Speed Flash Microcontrollers |
| DS89C450-MNL | Ultra-High-Speed Flash Microcontrollers |
| DS89C450-QNL | Ultra-High-Speed Flash Microcontrollers |
| DS89C430-DS89C450 | Ultra-High-Speed Flash Microcontrollers |
相關代理商/技術參數 |
參數描述 |
|---|---|
| DS89C440-MNL+ | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| DS89C440-QNG | 功能描述:IC MCU FLASH 32KB 25MHZ 44-PLCC RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器， 系列:89C 產品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:260 系列:73S12xx 核心處理器:80515 芯體尺寸:8-位 速度:24MHz 連通性:I²C，智能卡，UART/USART，USB 外圍設備:LED，POR，WDT 輸入/輸出數:9 程序存儲器容量:64KB（64K x 8） 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:2K x 8 電壓 - 電源 (Vcc/Vdd):2.7 V ~ 5.5 V 數據轉換器:- 振蕩器型:內部 工作溫度:-40°C ~ 85°C 封裝/外殼:68-VFQFN 裸露焊盤 包裝:管件 |
| DS89C440-QNL | 功能描述:IC MCU FLASH 32KB 33MHZ 44-PLCC RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器， 系列:89C 產品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:260 系列:73S12xx 核心處理器:80515 芯體尺寸:8-位 速度:24MHz 連通性:I²C，智能卡，UART/USART，USB 外圍設備:LED，POR，WDT 輸入/輸出數:9 程序存儲器容量:64KB（64K x 8） 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:2K x 8 電壓 - 電源 (Vcc/Vdd):2.7 V ~ 5.5 V 數據轉換器:- 振蕩器型:內部 工作溫度:-40°C ~ 85°C 封裝/外殼:68-VFQFN 裸露焊盤 包裝:管件 |
| DS89C440-QNL+ | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Ultra-High-Speed Flash Microcontrollers |
| DS89C440-XXX | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Ultra-High-Speed Flash Microcontrollers |
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