熔丝位(Fuse)入门

AVR Studio 中 STK500 处理熔丝位有巨大的优势：它是以功能组合让用户配置。 这种方式与小马(PnoyProg2000,SL-ISP)相比，具有以下的优势(优势是如此明显，可以用“巨大优势”来形容)：     1. 有效避免因不熟悉熔丝位让芯片锁死 (这是初学者的恶梦)     2. 不需要靠记忆与查文档，就能配置熔丝位(这也是初学者的恶梦)这是我们网站为何推荐使用STK500下载器的又一原因。

操作界面如下： (注意：下图中，打勾的表示选中，代表0。没有打勾的表示1)。

上图的资料整理如下(该表下面有中文翻译与说明)：

On-Chip Debug Enabled; [OCDEN=0]

JTAG Interface Enabled; [JTAGEN=0]

Serial program downloading (SPI) enabled; [SPIEN=0]

Preserve EEPROM memory through the Chip Erase cycle; [EESAVE=0]

Boot Flash section size=128 words Boot start address=$1F80; [BOOTSZ=11]

Boot Flash section size=256 words Boot start address=$1F00; [BOOTSZ=10]

Boot Flash section size=512 words Boot start address=$1E00; [BOOTSZ=01]

Boot Flash section size=1024 words Boot start address=$1C00; [BOOTSZ=00] ; default value

Boot Reset vector Enabled (default address=$0000); [BOOTRST=0]

CKOPT fuse (operation dependent of CKSEL fuses); [CKOPT=0]

Brown-out detection level at VCC=4.0 V; [BODLEVEL=0]

Brown-out detection level at VCC=2.7 V; [BODLEVEL=1]

Brown-out detection enabled; [BODEN=0]

Ext. Clock; Start-up time: 6 CK + 0 ms; [CKSEL=0000 SUT=00]

Ext. Clock; Start-up time: 6 CK + 4 ms; [CKSEL=0000 SUT=01]

Ext. Clock; Start-up time: 6 CK + 64 ms; [CKSEL=0000 SUT=10]

Int. RC Osc. 1 MHz; Start-up time: 6 CK + 0 ms; [CKSEL=0001 SUT=00]

Int. RC Osc. 1 MHz; Start-up time: 6 CK + 4 ms; [CKSEL=0001 SUT=01]

Int. RC Osc. 1 MHz; Start-up time: 6 CK + 64 ms; [CKSEL=0001 SUT=10]; default value

Int. RC Osc. 2 MHz; Start-up time: 6 CK + 0 ms; [CKSEL=0010 SUT=00]

Int. RC Osc. 2 MHz; Start-up time: 6 CK + 4 ms; [CKSEL=0010 SUT=01]

Int. RC Osc. 2 MHz; Start-up time: 6 CK + 64 ms; [CKSEL=0010 SUT=10]

Int. RC Osc. 4 MHz; Start-up time: 6 CK + 0 ms; [CKSEL=0011 SUT=00]

Int. RC Osc. 4 MHz; Start-up time: 6 CK + 4 ms; [CKSEL=0011 SUT=01]

Int. RC Osc. 4 MHz; Start-up time: 6 CK + 64 ms; [CKSEL=0011 SUT=10]

Int. RC Osc. 8 MHz; Start-up time: 6 CK + 0 ms; [CKSEL=0100 SUT=00]

Int. RC Osc. 8 MHz; Start-up time: 6 CK + 4 ms; [CKSEL=0100 SUT=01]

Int. RC Osc. 8 MHz; Start-up time: 6 CK + 64 ms; [CKSEL=0100 SUT=10]

Ext. RC Osc. - 0.9 MHz; Start-up time: 18 CK + 0 ms; [CKSEL=0101 SUT=00]

Ext. RC Osc. - 0.9 MHz; Start-up time: 18 CK + 4 ms; [CKSEL=0101 SUT=01]

Ext. RC Osc. - 0.9 MHz; Start-up time: 18 CK + 64 ms; [CKSEL=0101 SUT=10]

Ext. RC Osc. - 0.9 MHz; Start-up time: 6 CK + 4 ms; [CKSEL=0101 SUT=11]

Ext. RC Osc. 0.9 MHz - 3.0 MHz; Start-up time: 18 CK + 0 ms; [CKSEL=0110 SUT=00]

Ext. RC Osc. 0.9 MHz - 3.0 MHz; Start-up time: 18 CK + 4 ms; [CKSEL=0110 SUT=01]

Ext. RC Osc. 0.9 MHz - 3.0 MHz; Start-up time: 18 CK + 64 ms; [CKSEL=0110 SUT=10]

Ext. RC Osc. 0.9 MHz - 3.0 MHz; Start-up time: 6 CK + 4 ms; [CKSEL=0110 SUT=11]

Ext. RC Osc. 3.0 MHz - 8.0 MHz; Start-up time: 18 CK + 0 ms; [CKSEL=0111 SUT=00]

Ext. RC Osc. 3.0 MHz - 8.0 MHz; Start-up time: 18 CK + 4 ms; [CKSEL=0111 SUT=01]

Ext. RC Osc. 3.0 MHz - 8.0 MHz; Start-up time: 18 CK + 64 ms; [CKSEL=0111 SUT=10]

Ext. RC Osc. 3.0 MHz - 8.0 MHz; Start-up time: 6 CK + 4 ms; [CKSEL=0111 SUT=11]

Ext. RC Osc. 8.0 MHz - 12.0 MHz; Start-up time: 18 CK + 0 ms; [CKSEL=1000 SUT=00]

Ext. RC Osc. 8.0 MHz - 12.0 MHz; Start-up time: 18 CK + 4 ms; [CKSEL=1000 SUT=01]

Ext. RC Osc. 8.0 MHz - 12.0 MHz; Start-up time: 18 CK + 64 ms; [CKSEL=1000 SUT=10]

Ext. RC Osc. 8.0 MHz - 12.0 MHz; Start-up time: 6 CK + 4 ms; [CKSEL=1000 SUT=11]

Ext. Low-Freq. Crystal; Start-up time: 1K CK + 4 ms; [CKSEL=1001 SUT=00]

Ext. Low-Freq. Crystal; Start-up time: 1K CK + 64 ms; [CKSEL=1001 SUT=01]

Ext. Low-Freq. Crystal; Start-up time: 32K CK + 64 ms; [CKSEL=1001 SUT=10]

Ext. Crystal/Resonator Low Freq.; Start-up time: 258 CK + 4 ms; [CKSEL=1010 SUT=00]

Ext. Crystal/Resonator Low Freq.; Start-up time: 258 CK + 64 ms; [CKSEL=1010 SUT=01]

Ext. Crystal/Resonator Low Freq.; Start-up time: 1K CK + 0 ms; [CKSEL=1010 SUT=10]

Ext. Crystal/Resonator Low Freq.; Start-up time: 1K CK + 4 ms; [CKSEL=1010 SUT=11]

Ext. Crystal/Resonator Low Freq.; Start-up time: 1K CK + 64 ms; [CKSEL=1011 SUT=00]

Ext. Crystal/Resonator Low Freq.; Start-up time: 16K CK + 0 ms; [CKSEL=1011 SUT=01]

Ext. Crystal/Resonator Low Freq.; Start-up time: 16K CK + 4 ms; [CKSEL=1011 SUT=10]

Ext. Crystal/Resonator Low Freq.; Start-up time: 16K CK + 64 ms; [CKSEL=1011 SUT=11]

Ext. Crystal/Resonator Medium Freq.; Start-up time: 258 CK + 4 ms; [CKSEL=1100 SUT=00]

Ext. Crystal/Resonator Medium Freq.; Start-up time: 258 CK + 64 ms; [CKSEL=1100 SUT=01]

Ext. Crystal/Resonator Medium Freq.; Start-up time: 1K CK + 0 ms; [CKSEL=1100 SUT=10]

Ext. Crystal/Resonator Medium Freq.; Start-up time: 1K CK + 4 ms; [CKSEL=1100 SUT=11]

Ext. Crystal/Resonator Medium Freq.; Start-up time: 1K CK + 64 ms; [CKSEL=1101 SUT=00]

Ext. Crystal/Resonator Medium Freq.; Start-up time: 16K CK + 0 ms; [CKSEL=1101 SUT=01]

Ext. Crystal/Resonator Medium Freq.; Start-up time: 16K CK + 4 ms; [CKSEL=1101 SUT=10]

Ext. Crystal/Resonator Medium Freq.; Start-up time: 16K CK + 64 ms; [CKSEL=1101 SUT=11]

Ext. Crystal/Resonator High Freq.; Start-up time: 258 CK + 4 ms; [CKSEL=1110 SUT=00]

Ext. Crystal/Resonator High Freq.; Start-up time: 258 CK + 64 ms; [CKSEL=1110 SUT=01]

Ext. Crystal/Resonator High Freq.; Start-up time: 1K CK + 0 ms; [CKSEL=1110 SUT=10]

Ext. Crystal/Resonator High Freq.; Start-up time: 1K CK + 4 ms; [CKSEL=1110 SUT=11]

Ext. Crystal/Resonator High Freq.; Start-up time: 1K CK + 64 ms; [CKSEL=1111 SUT=00]

Ext. Crystal/Resonator High Freq.; Start-up time: 16K CK + 0 ms; [CKSEL=1111 SUT=01]

Ext. Crystal/Resonator High Freq.; Start-up time: 16K CK + 4 ms; [CKSEL=1111 SUT=10]

Ext. Crystal/Resonator High Freq.; Start-up time: 16K CK + 64 ms; [CKSEL=1111 SUT=11]

上表的英文翻译说明如下：

英文	中文
On-Chip Debug Enabled	片内 调试 使能
JTAG Interface Enabled	JTAG 接口 使能
Serial program downloading (SPI) enabled	串行编程下载(SPI) 使能 (ISP下载时该位不能修改)
Preserve EEPROM memory through the Chip Erase cycle;	芯片擦除时EEPROM的内容保留
Boot Flash section size=xxxx words	引导(Boot)区大小为xxx个词
Boot start address=$yyyy;	引导(Boot)区开始地址为 $yyyy
Boot Reset vector Enabled	引导(Boot)、复位 向量 使能
Brown-out detection level at VCC=xxxx V;	掉电检测的电平为 VCC=xxxx 伏
Brown-out detection enabled;	掉电检测使能
Start-up time: xxx CK + yy ms	启动时间 xxx 个时钟周期 + yy 毫秒
Ext. Clock;	外部时钟
Int. RC Osc.	内部 RC(阻容) 振荡器
Ext. RC Osc.	外部 RC(阻容) 振荡器
Ext. Low-Freq. Crystal;	外部 低频 晶体
Ext. Crystal/Resonator Low Freq	外部晶体/陶瓷振荡器 低频
Ext. Crystal/Resonator Medium Freq	外部晶体/陶瓷振荡器 中频
Ext. Crystal/Resonator High Freq	外部晶体/陶瓷振荡器 高频

注：以上中文是对照 ATmega16的中、英文版本数据手册而翻译。尽量按照了官方的中文术语。

应用举例：

比如我们想使用片内的RC振荡(即不需要接晶振)，可以选择选择下面三者之一：    Int. RC Osc. 8 MHz; Start-up time: 6 CK + 0 ms; [CKSEL=0100 SUT=00]    Int. RC Osc. 8 MHz; Start-up time: 6 CK + 4 ms; [CKSEL=0100 SUT=01]    Int. RC Osc. 8 MHz; Start-up time: 6 CK + 64 ms; [CKSEL=0100 SUT=10]比如我们想使用外部7.3728M晶振，可以选择选择下面三者之一：    Ext. Crystal/Resonator High Freq.; Start-up time: 258 CK + 4 ms; [CKSEL=1110 SUT=00]    或后面与Ext. Crystal/Resonator High Freq.;.... 有关的选择。