LFSTBEB7660 Freescale Semiconductor, LFSTBEB7660 Datasheet - Page 23

• Manufacturer Part Number: LFSTBEB7660
• Description: BOARD DEV ACCELEROMETR MMA7660
• Manufacturer: Freescale Semiconductor

Specifications of LFSTBEB7660

• Sensor Type: Accelerometer, 3 Axis
• Sensing Range: ±1.5g
• Interface: USB
• Sensitivity: 21.33 count/g
• Voltage - Supply: 5V, USB
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: MMA7660
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Acknowledge
data. Thus each byte transferred effectively requires 9-bits. The master generates the 9
SDA during the acknowledge clock tap, such that the SDA line is stable low during the high period of the clock tap. When the
master is transmitting to MMA7660FC, it generates the acknowledge bit because it is the recipient. When the device is
transmitting to the master, the master generates the acknowledge bit because the master is the recipient.
The Slave Address
R/W bit, which is low for a write command and high for a read command. The device has a factory set I
is normally 1001100 (0x4C). Contact the factory to request a different I
to 1110111 (0x08 to 0xEF), by metal mask option.
recognizes its slave address, it acknowledges and is then ready for continued communication.
Message Format for Writing MMA7660FC
by at least one byte of information. The first byte of information is the register address of the first internal register that is to be
updated. The Master Write address is 1001 1000 (0x98). If a STOP condition is detected after just the register address is
received, then MMA7660FC takes no action. See
0x00 when a STOP condition is detected, so a single byte write has no net effect because the register address given in this first
and only byte is replaced by 0x00 at the STOP condition. The internal register address pointer is not, however, cleared on a
repeated start condition. Use a single byte write followed by a repeated start to read back data from a register.
selected by the register address. See
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Freescale Semiconductor
The acknowledge bit is a clocked 9th bit, shown in
MMA7660FC has a 7-bit long slave address, shown in
The device monitors the bus continuously, waiting for a START condition followed by its slave address. When the device
A write to MMA7660FC comprises the transmission of the device’s keyscan slave address with the R/W bit set to 0, followed
Any bytes received after the register address are data bytes. The first data byte goes into the internal register of the device
BY TRANSMITTER
BY RECEIVER
Master
Slave
SDA
SCL
SDA
SDA
SCL
ST
CONDITION
START
MSB
Device Address [6:0]
1
S
0
Figure
1
12.
0
W
Figure 12. Single Byte Write
Figure
Figure 11. Slave Address
Figure 10. Acknowledge
Figure
AK
1
12. MMA7660FC clears its internal register address pointer to register
Figure
2
10, which the recipient uses to handshake a receipt of each byte of
11. The bit following the 7-bit slave address (bit eight) is the
Register Address [6:0]
1
2
C slave address, which is available in the range 0001000
ACKNOWLEDGEMENT
0
CLOCK PULSE FOR
CLOCK TAP FOR
0
AK
th
8
clock tap, and the recipient pulls down
R/W
Data [7:0]
2
ACK
9
C slave address which
AK
MMA7660FC
SP
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