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參數(shù)資料
| 型號： | DS80C323-END |
| 廠商： | Maxim Integrated Products |
| 文件頁數(shù)： | 4/38頁 |
| 文件大小： | 0K |
| 描述： | IC MCU HI SPEED 18MHZ IND 44TQFP |
| 產(chǎn)品培訓(xùn)模塊： | Lead (SnPb) Finish for COTS |
| 產(chǎn)品變化通告： | Product Discontinuation 20/Feb/2012 |
| 標(biāo)準(zhǔn)包裝： | 160 |
| 系列： | 80C |
| 核心處理器： | 8051 |
| 芯體尺寸： | 8-位 |
| 速度： | 18MHz |
| 連通性： | EBI/EMI，SIO，UART/USART |
| 外圍設(shè)備： | 電源故障復(fù)位，WDT |
| 輸入/輸出數(shù)： | 32 |
| 程序存儲器類型： | ROMless |
| RAM 容量： | 256 x 8 |
| 電壓 - 電源 (Vcc/Vdd)： | 4.5 V ~ 5.5 V |
| 振蕩器型： | 外部 |
| 工作溫度： | -40°C ~ 85°C |
| 封裝/外殼： | 44-TQFP |
| 包裝： | 托盤 |
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DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
12 of 38
STRETCH MEMORY CYCLE
The DS80C320/DS80C323 allow the application software to adjust the speed of data memory access. The
microcontroller is capable of performing the MOVX in as little as two instruction cycles. However, this
value can be stretched as needed so that both fast memory and slow memory or peripherals can be
accessed with no glue logic. Even in high-speed systems, it may not be necessary or desirable to perform
data memory access at full speed. In addition, there are a variety of memory-mapped peripherals such as
LCD displays or UARTs that are not fast.
The Stretch MOVX is controlled by the Clock Control Register at SFR location 8Eh as described below.
This allows the user to select a stretch value between 0 and 7. A Stretch of 0 will result in a two-machine
cycle MOVX. A Stretch of 7 will result in a MOVX of nine machine cycles. Software can dynamically
change this value depending on the particular memory or peripheral.
On reset, the Stretch value will default to 1, resulting in a three-cycle MOVX. Therefore, RAM access
will not be performed at full speed. This is a convenience to existing designs that may not have fast RAM
in place. When maximum speed is desired, the software should select a Stretch value of 0. When using
very slow RAM or peripherals, a larger stretch value can be selected. Note that this affects data memory
only and the only way to slow program memory (ROM) access is to use a slower crystal.
Using a Stretch value between 1 and 7 causes the microcontroller to stretch the read/write strobe and all
related timing. This results in a wider read/write strobe allowing more time for memory/peripherals to
respond. The timing of the variable speed MOVX is shown in the Electrical Specifications section. Note
that full speed access is not the reset default case. Table 2 shows the resulting strobe widths for each
Stretch value. The memory stretch is implemented using the Clock Control special-function register at
SFR location 8Eh. The stretch value is selected using bits CKCON.2–0. In the table, these bits are
referred to as M2 through M0. The first stretch (default) allows the use of common 120ns or 150ns RAMs
without dramatically lengthening the memory access.
Table 2. Data Memory Cycle Stretch Values
CKCON.2–0
MD2
MD1
MD0
MEMORY
CYCLES
RD
or WR STROBE
WIDTH IN CLOCKS
STROBE WIDTH
TIME AT 25MHz
(ns)
0
2
80
0
1
3 (default)
4
160
0
1
0
4
8
320
0
1
5
12
480
1
0
6
16
640
1
0
1
7
20
800
1
0
8
24
960
1
9
28
1120
相關(guān)PDF資料 |
PDF描述 |
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| DS80C320-ENG | IC MCU HI SPEED 25MHZ IND 44TQFP |
| DS89C450-ENG | IC MCU FLASH 64KB 25MHZ 44-TQFP |
| DS89C440-QNL | IC MCU FLASH 32KB 33MHZ 44-PLCC |
| DS89C440-QNG | IC MCU FLASH 32KB 25MHZ 44-PLCC |
| DS89C440-MNL | IC MCU FLASH 32KB 33MHZ 40-DIP |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS80C323-END+ | 功能描述:8位微控制器 -MCU High-Speed Low-Power RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT |
| DS80C323ENG | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Microprocessor |
| DS80C323-ENG | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:High-Speed Microcontroller User Guide |
| DS80C323-ENL | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:High-Speed Microcontroller User Guide |
| DS80C323-ENR | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:High-Speed Microcontroller User Guide |
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