MMA8450QT Freescale Semiconductor, MMA8450QT Datasheet - Page 22

• Manufacturer Part Number: MMA8450QT
• Description: Board Mount Accelerometers 12bit 3-Axis FIFO HPF PL
• Manufacturer: Freescale Semiconductor

Specifications of MMA8450QT

• Sensing Axis: X, Y, Z
• Acceleration: 2 g, 4 g, 8 g
• Digital Output - Number Of Bits: 12 bit
• Supply Voltage (max): 1.89 V
• Supply Voltage (min): 1.71 V
• Supply Current: 3 uA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Shutdown: Yes
• Sensitivity: 0.976 mg/digit, 1.953 mg/digit, 3.906 mg/digit
• Package / Case: QFN-16
• Output Type: Digital
• Package Type: QFN
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Product Depth (mm): 3mm
• Product Height (mm): 1mm
• Product Length (mm): 3mm
• Mounting: Surface Mount
• Pin Count: 16
• Acceleration Range: ± 2g, ± 4g, ± 8g
• No. Of Axes: 3
• Ic Interface Type: I2C, Serial
• Sensor Case Style: QFN
• No. Of Pins: 16
• Supply Voltage Range: 1.71V To 1.89V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

6.1
to application note, AN3922.
0x00, 0x04, 0x0B: STATUS Registers
.
should all be the same value and reflect the real-time status information of the X, Y and Z sample data. When FDE is set (the
FIFO is on) Register 0x00, 0x04 and 0x10 will have the same value and 0x0B will reflect the status of the transient data. The
aliases allow the STATUS register to be read easily before reading the current 8-bit, 12-bit, or FIFO sample data using the register
address auto-incrementing mechanism.
Table 12. STATUS Description
ZYXOW is set whenever a new acceleration data is produced before completing the retrieval of the previous set. This event
occurs when the content of at least one acceleration data register (i.e., OUT_X, OUT_Y, OUT_Z) has been overwritten. ZYXOW
is cleared when the high-bytes of the acceleration data (OUT_X_MSB, OUT_Y_MSB, OUT_Z_MSB) of all the active channels
are read.
ZOW is set whenever a new acceleration sample related to the Z-axis is generated before the retrieval of the previous sample.
When this occurs the previous sample is overwritten. ZOW is cleared anytime OUT_Z_MSB register is read.
YOW is set whenever a new acceleration sample related to the Y-axis is generated before the retrieval of the previous sample.
When this occurs the previous sample is overwritten. YOW is cleared anytime OUT_Y_MSB register is read.
XOW is set whenever a new acceleration sample related to the X-axis is generated before the retrieval of the previous sample.
When this occurs the previous sample is overwritten. XOW is cleared anytime OUT_X_MSB register is read.
ZYXDR signals that a new sample for any of the enabled channels is available. ZYXDR is cleared when the high-bytes of the
acceleration data (OUT_X_MSB, OUT_Y_MSB, OUT_Z_MSB) of all the enabled channels are read.
ZDR is set whenever a new acceleration sample related to the Z-axis is generated. ZDR is cleared anytime OUT_Z_MSB register
is read. In order to enable the monitoring and assertion of this bit, the ZDR bit requires the Z-axis event detection flag to be
enabled (bit ZDEFE = 1 inside XYZ_DATA_CFG register).
22
Alias for DR_Status (0x0B) or F_Status (0x10) (Read Only)
MMA8450Q
0X00, 0X04, 0X0B STATUS: Data Status Registers (Read Only)
The following are the data registers for the MMA8450Q. For more information on data manipulation of the MMA8450Q, refer
When FDE bit found in register 0x16 (XYZ_DATA_CFG), bit 7 is cleared (the FIFO is not on) register 0x00, 0x04 and 0x0B
ZYXOW
ZYXOW
ZYXDR
Bit 7
ZOW
YOW
XOW
ZDR
YDR
XDR
FDE (FIFO Data Enable Bit 7, Reg 0x16) Setting
Data Registers
X, Y, Z-axis Data Overwrite. Default value: 0
0: No data overwrite has occurred
1: Previous X, Y, or Z data was overwritten by new X, Y, or Z data before it was read
Z-axis Data Overwrite. Default value: 0
0: No data overwrite has occurred
1: Previous Z-axis data was overwritten by new Z-axis data before it was read
Y-axis Data Overwrite. Default value: 0
0: No data overwrite has occurred
1: Previous Y-axis data was overwritten by new Y-axis data before it was read
X-axis Data Overwrite. Default value: 0
0: No data overwrite has occurred
1: Previous X-axis data was overwritten by new X-axis data before it was read
X, Y, Z-axis new Data Ready. Default value: 0
0: No new set of data ready
1: A new set of data is ready
Z-axis new Data Available. Default value: 0
0: No new Z-axis data is ready
1: A new Z-axis data is ready
Z-axis new Data Available. Default value: 0
0: No new Y-axis data ready
1: A new Y-axis data is ready
Z-axis new Data Available. Default value: 0
0: No new X-axis data ready
1: A new X-axis data is ready
ZOW
Bit 6
FDE = 0
FDE = 1
YOW
Bit 5
XOW
Bit 4
ZYXDR
Bit 3
0x00 = 0x04 = DR_STATUS (0x0B)
0x00 = 0x04 = F_STATUS (0x10)
Bit 2
ZDR
Alias Status
Bit 1
YDR
Freescale Semiconductor
Bit 0
XDR
Sensors