收藏本站
6.7
Auto-WAKE/SLEEP Detection
The ASLP_COUNT register sets the minimum time period of inactivity required to change current ODR value from the value
specified in the DR[2:0] register to ASLP_RATE register value, provided the SLPE bit is set to a logic ‘1’ in the CTRL_REG2
register. See Table 59 for functional blocks that may be monitored for inactivity in order to trigger the “return to SLEEP” event.
0x29: ASLP_COUNT Register (Read/Write)
Bit 7
D7
Bit 6
D6
Bit 5
D5
Bit 4
D4
Bit 3
D3
Bit 2
D2
Bit 1
D1
Bit 0
D0
Table 58. ASLP_COUNT Description
D[7:0]
Duration value. Default value: 0000_0000.
D7-D0 defines the minimum duration time to change current ODR value from DR to ASLP_RATE . Time step and maximum
value depend on the ODR chosen as shown in Table 59 .
Table 59. ASLP_COUNT Relationship with ODR
Output Data Rate
(ODR)
800 Hz
400 Hz
200 Hz
100 Hz
50 Hz
12.5 Hz
6.25 Hz
1.56 Hz
Duration
0 to 81s
0 to 81s
0 to 81s
0 to 81s
0 to 81s
0 to 81s
0 to 81s
0 to 162s
ODR Time Step
1.25 ms
2.5 ms
5 ms
10 ms
20 ms
80 ms
160 ms
640 ms
ASLP_COUNT Step
320 ms
320 ms
320 ms
320 ms
320 ms
320 ms
320 ms
640 ms
Table 60. SLEEP/WAKE Mode Gates and Triggers
Interrupt Source
FIFO_GATE
SRC_TRANS
SRC_LNDPRT
SRC_PULSE
SRC_FF_MT
SRC_ASLP
SRC_DRDY
Event restarts timer and
delays Return to SLEEP
Yes
Yes
Yes
Yes
Yes
No*
No
Event will WAKE from SLEEP
No
Yes
Yes
Yes
Yes
No*
No
* If the FIFO_GATE bit is set to logic ‘1’, the assertion of the SRC_ASLP interrupt does not prevent
the system from transitioning to SLEEP or from WAKE mode; instead it prevents the FIFO buffer from
accepting new sample data until the host application flushes the FIFO buffer.
In order to wake the device, the desired function or functions must be enabled in CTRL_REG4 and set to WAKE to SLEEP in
CTRL_REG3. All enabled functions will still function in SLEEP mode at the SLEEP ODR. Only the functions that have been
selected for WAKE from SLEEP will WAKE the device.
MMA8451Q has four functions that can be used to keep the sensor from falling asleep; Transient, Orientation, Tap and Motion/
Freefall. One or more of these functions can be enabled. In order to WAKE the device, four functions are provided; Transient,
Orientation, Tap, and the Motion/Freefall. Note that the FIFO does not WAKE the device. The Auto-WAKE/SLEEP interrupt does
not affect the WAKE/SLEEP, nor does the data ready interrupt. The FIFO gate (bit 7) in Register 0x2C, when set, will hold the last
data in the FIFO before transitioning to a different ODR. After the buffer is flushed, it will accept new sample data at the current
ODR. See Register 0x2C for the WAKE from SLEEP bits.
If the Auto-SLEEP bit is disabled, then the device can only toggle between STANDBY and WAKE mode. If Auto-SLEEP
interrupt is enabled, transitioning from ACTIVE mode to Auto-SLEEP mode and vice versa generates an interrupt.
MMA8451Q
Sensors
Freescale Semiconductor, Inc.
41
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
MMA8452QR1 IC ACCELER 2G/4G/8G 3AXIS 16QFN
MMA8453QR1 IC ACCELER 2G/4G/8G 3AXIS 16QFN
MMBF0201NLT1 MOSFET N-CH 20V 300MA SOT-23
MMBF170-7 MOSFET N-CH 60V 500MA SOT23-3
MMBF170LT1 MOSFET N-CH 60V 500MA SOT-23
MMBF170 MOSFET N-CH 60V 500MA SOT-23
MMBF2201NT1 MOSFET N-CH 20V 300MA SOT-323
MMBF2202PT1 MOSFET P-CH 20V 300MA SOT-323
相关代理商/技术参数
MMA8452Q 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:3-Axis, 12-bit/8-bit Digital Accelerometer
MMA8452QR1 功能描述:加速计 - 板上安装 LOW G 3-AXIS 12BT EX VLT RoHS:否 制造商:Murata 传感轴:Double 加速:12 g 灵敏度: 封装 / 箱体: 输出类型:Analog 数字输出 - 位数:11 bit 电源电压-最大:5.25 V 电源电压-最小:4.75 V 电源电流:4 mA 最大工作温度:+ 125 C 最小工作温度:- 40 C
MMA8452QT 功能描述:加速计 - 板上安装 LOW G 3-AXIS 12BT EX VLT RoHS:否 制造商:Murata 传感轴:Double 加速:12 g 灵敏度: 封装 / 箱体: 输出类型:Analog 数字输出 - 位数:11 bit 电源电压-最大:5.25 V 电源电压-最小:4.75 V 电源电流:4 mA 最大工作温度:+ 125 C 最小工作温度:- 40 C
MMA8453Q 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:Xtrinsic MMA8453Q 3-Axis, 10-bit/8-bit Digital Accelerometer
MMA8453QR1 功能描述:加速计 - 板上安装 LOW G 3-AXIS DGTL ACCEL RoHS:否 制造商:Murata 传感轴:Double 加速:12 g 灵敏度: 封装 / 箱体: 输出类型:Analog 数字输出 - 位数:11 bit 电源电压-最大:5.25 V 电源电压-最小:4.75 V 电源电流:4 mA 最大工作温度:+ 125 C 最小工作温度:- 40 C
MMA8453QT 功能描述:加速计 - 板上安装 LOW G 3-AXIS DGTL ACCEL RoHS:否 制造商:Murata 传感轴:Double 加速:12 g 灵敏度: 封装 / 箱体: 输出类型:Analog 数字输出 - 位数:11 bit 电源电压-最大:5.25 V 电源电压-最小:4.75 V 电源电流:4 mA 最大工作温度:+ 125 C 最小工作温度:- 40 C
MMA8491Q 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:Xtrinsic MMA8491Q 3-Axis Multifunction Digital Accelerometer
MMA8491QR1 功能描述:加速计 - 板上安装 3-Axis Low Voltage Discrete Tilt Sensor RoHS:否 制造商:Murata 传感轴:Double 加速:12 g 灵敏度: 封装 / 箱体: 输出类型:Analog 数字输出 - 位数:11 bit 电源电压-最大:5.25 V 电源电压-最小:4.75 V 电源电流:4 mA 最大工作温度:+ 125 C 最小工作温度:- 40 C