TI中文支持网咨询一点问题：
我想要做一些低功耗的设备，关于硬件方面有没有什么需要注意的地方？功耗尽量降到最低
YiKai Chen：
基本上都是軟體設定，硬體上面應該還好
user5355203：
回复 YiKai Chen:
如果我想不使用32.768KHZ的外部晶振，请问一下，软件改怎么设置？我使用的是PM2 休眠模式，不使用外部晶振，会不会造成什么影响？
user5355203：
请教一下，我想要在ZStack 1.2.2a中不使用外部32KHZ的晶振，程序中需要怎么设置？关闭外部晶振会造成什么影响吗？
YiKai Chen：
可以參考CC2530 user guide的說明
4.4.3 32-kHz Oscillators
Two 32-kHz oscillators are present in the device as clock sources for the 32-kHz clock:
• 32-kHz XOSC
• 32-kHz RCOSC
By default, after a reset, the 32-kHz RCOSC is enabled and selected as the 32-kHz clock source. The
RCOSC consumes less power, but is less accurate compared to the 32-kHz XOSC. The chosen 32-kHz
clock source drives the Sleep Timer, generates the tick for the Watchdog Timer, and is used as a strobe in
Timer 2 to calculate the Sleep Timer sleep time. The CLKCONCMD.OSC32K register bit selects the
oscillator to be used as the 32-kHz clock source. This bit does not give an indication of the stability of the
32-kHz XOSC.
The CLKCONCMD.OSC32K register bit can be written at any time, but does not take effect before the 16-
MHz RCOSC is the active system clock source. When system clock is changed from the 16-MHz RCOSC
to the 32-MHz XOSC (CLKCONCMD.OSC from 1 to 0), calibration of the 32-kHz RCOSC starts up and is
performed once if the 32-kHz RCOSC is selected. During calibration, a divided version of the 32-MHz
XOSC is used. The result of the calibration is that the 32-kHz RSOSC is running at 32.753 kHz. The 32-
kHz RCOSC calibration may take up to 2 ms to complete. Calibration can be disabled by setting
SLEEPCMD.OSC32K_CALDIS to 1. At the end of the calibration, an extra pulse may occur on the 32-kHz
clock source, which causes the sleep timer to be incremented by 1.
Note that after having switched to the 32-kHz XOSC and when coming up from PM3 with the 32-kHz
XOSC enabled, the oscillator requires up to 500 ms to stabilize on the correct frequency. The Sleep
Timer, Watchdog Timer and clock-loss detector should not be used before the 32-kHz XOSC is stable.
YiKai Chen：
回复 user5355203:
可以參考CC2530 user guide的說明
4.4.3 32-kHz Oscillators
Two 32-kHz oscillators are present in the device as clock sources for the 32-kHz clock:
• 32-kHz XOSC
• 32-kHz RCOSC
By default, after a reset, the 32-kHz RCOSC is enabled and selected as the 32-kHz clock source. The
RCOSC consumes less power, but is less accurate compared to the 32-kHz XOSC. The chosen 32-kHz
clock source drives the Sleep Timer, generates the tick for the Watchdog Timer, and is used as a strobe in
Timer 2 to calculate the Sleep Timer sleep time. The CLKCONCMD.OSC32K register bit selects the
oscillator to be used as the 32-kHz clock source. This bit does not give an indication of the stability of the
32-kHz XOSC.
The CLKCONCMD.OSC32K register bit can be written at any time, but does not take effect before the 16-
MHz RCOSC is the active system clock source. When system clock is changed from the 16-MHz RCOSC
to the 32-MHz XOSC (CLKCONCMD.OSC from 1 to 0), calibration of the 32-kHz RCOSC starts up and is
performed once if the 32-kHz RCOSC is selected. During calibration, a divided version of the 32-MHz
XOSC is used. The result of the calibration is that the 32-kHz RSOSC is running at 32.753 kHz. The 32-
kHz RCOSC calibration may take up to 2 ms to complete. Calibration can be disabled by setting
SLEEPCMD.OSC32K_CALDIS to 1. At the end of the calibration, an extra pulse may occur on the 32-kHz
clock source, which causes the sleep timer to be incremented by 1.
Note that after having switched to the 32-kHz XOSC and when coming up from PM3 with the 32-kHz
XOSC enabled, the oscillator requires up to 500 ms to stabilize on the correct frequency. The Sleep
Timer, Watchdog Timer and clock-loss detector should not be used before the 32-kHz XOSC is stable.
gaoyang9992006：
硬件上要考虑好功耗控制问题，这牵涉到你具体要实现什么功能，用什么电路实现，比较CC2530只是控制和无线传输，其他需要外部电路实现的部分要完全受控，另外有模电的部分也要考虑好功耗问题。
user4637920：
CC2530已经选定了，硬件参数已经定了，所以硬件没啥可注意的。
在软件上，降低发送次数，空闲时进入休眠状态；关闭不必要的外设时钟等。
Viki Shi：
用内部晶振的话，精确度方面稍有不足。你看一下应用对这块是否有要求，大部分是推荐用外部的
user4049846：
在硬件基本上差不多的条件下，要想解决低功耗的问题，可以从以下两个方面着手：
1.软件算法
2.电路拓扑
user450161651：
软件上设置低功耗的睡眠模式，关掉不适用的I/O口，降低时钟频率等
