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參數(shù)資料
| 型號： | DS80C411-FNY+ |
| 廠商： | Maxim Integrated Products |
| 文件頁數(shù)： | 101/102頁 |
| 文件大小： | 0K |
| 描述： | IC MCU 75MHZ 16MB HP 100-LQFP |
| 產(chǎn)品培訓(xùn)模塊： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 標(biāo)準(zhǔn)包裝： | 90 |
| 系列： | 80C |
| 核心處理器： | 8051 |
| 芯體尺寸： | 8-位 |
| 速度： | 75MHz |
| 連通性： | 1 線，CAN，EBI/EMI，以太網(wǎng)，SIO，UART/USART |
| 外圍設(shè)備： | 電源故障復(fù)位，WDT |
| 輸入/輸出數(shù)： | 64 |
| 程序存儲器容量： | 64KB（64K x 8） |
| 程序存儲器類型： | ROM |
| RAM 容量： | 64K x 8 |
| 電壓 - 電源 (Vcc/Vdd)： | 1.62 V ~ 3.6 V |
| 振蕩器型： | 外部 |
| 工作溫度： | -40°C ~ 85°C |
| 封裝/外殼： | 100-LQFP |
| 包裝： | 托盤 |
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DS80C410/DS80C411 Network Microcontrollers with Ethernet and CAN
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Changing the System Clock/Machine Cycle Clock Frequency
The microcontroller incorporates a special locking sequence to ensure “glitch-free” switching of the internal clock
signals. All changes to the CD1, CD0 bits must pass through the 10 (divide-by-4) state. For example, to change
from 00 (frequency multiplier) to 11 (PMM), the software must change the bits in the following sequence: 00b =>
10b => 11b. Attempts to switch between invalid states fail, leaving the CD1, CD0 bits unchanged.
The following sequence must be followed when switching to the frequency multiplier as the internal time source.
This sequence can only be performed when the device is in divide-by-4 operation. The steps must be followed in
this order, although it is possible to have other instructions between them. Any deviation from this order causes the
CD1, CD0 bits to remain unchanged. Switching from frequency multiplier to nonmultiplier mode requires no steps
other than the changing of the CD1, CD0 bits.
1) Ensure that the CD1, CD0 bits are set to 10, and the RGMD (EXIF.2) bit = 0.
2) Clear the crystal multiplier enable (CTM) bit.
3) Set the 4X/2X bit to the appropriate state.
4) Set the CTM bit.
5) Poll the CKRDY bit (EXIF.3), waiting until it is set to 1. This takes approximately 65,536 cycles of the external
crystal or clock source.
6) Set CD1, CD0 to 00. The frequency multiplier is engaged on the machine cycle following the write to these bits.
Figure 21. System Clock Control Diagram
Switchback
As an alternative to software changing the CD1 and CD0 clock control bits to exit PMM, the microcontroller
provides hardware alternatives for automatic switchback to standard speed (divide-by-4) operation. When enabled,
the switchback feature allows serial ports and interrupts to automatically switch back from divide-by-1024 (PMM) to
divide-by-4 (standard speed) operation. This feature makes it very convenient to use the PMM in real-time
applications.
The switchback feature is enabled by setting the SFR bit SWB (PMR.5) to a 1. Once it is enabled, and PMM is
selected, two possible events can cause an automatic switchback to divide-by-4 mode. First, if an external interrupt
occurs and is acknowledged, the system clock reverts from PMM to divide-by-4 mode. For example, if INT0 is
enabled and the CPU is not servicing a higher priority interrupt, then switchback occurs on INT0. However, if INT0
is not enabled or the CPU is servicing a higher priority interrupt, then activity on INT0 does not cause switchback to
occur.
A switchback can also occur when an enabled UART detects the start bit, indicating the beginning of an incoming
serial character or when the SBUF register is loaded initiating a serial transmission. Note that a serial character’s
start bit does not generate an interrupt. The interrupt occurs only on reception of a complete serial word. The
automatic switchback on detection of a start bit allows hardware to return to divide-by-4 operation (and the correct
baud rate) in time for a proper serial reception or transmission.
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS80C411-FNY+ | 功能描述:8位微控制器 -MCU Network MCU w/Ethernet & CAN 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 |
| DS80CH11 | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:System Energy Manager |
| DS80CH11+E02 | 制造商:Maxim from Components Direct 功能描述:MAXIM DS80CH11+E02 SYSTEM ENERGY MANAGERS - Trays 制造商:Maxim 功能描述:Maxim DS80CH11+E02 System Energy Managers |
| DS80CH11-E02 | 制造商:Maxim from Components Direct 功能描述:MAXIM DS80CH11-E02 SYSTEM ENERGY MANAGERS - Trays 制造商:Maxim 功能描述:Maxim DS80CH11-E02 System Energy Managers |
| DS80E100 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:5 to 12.5 Gbps, Power-Saver Equalizer for Backplanes and Cables |
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