sx8661 Semtech Corporation, sx8661 Datasheet - Page 78

• Manufacturer Part Number: sx8661
• Description: Low Power, Capacitive Button Touch And Proximity Controller 8 Sensors With Led Drivers And Analog Output
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & SENSING
6.7 NVM burn
The content of the SPM can be copied permanently (burned) into the NVM to be used as the new default
parameters. The burning of the NVM can be done up to three times and must be done only when the SPM is
completely written with the desired data.
The number of times the NVM has been burned can be monitored by reading NvmCycle from the I2C register
GenStatLsb[7:5].
Figure 60 shows the simplified diagram of the NvmCycle counter. The SX8661 is delivered with empty NVM and
NvmCycle set to zero. The SPM points to the QSM.
Each NVM burn will increase the NvmCycle. At the fourth NVM burn the SX8661 switches definitely to the QSM.
The burning of the SPM into the NVM is done by executing a special sequence of four I2C commands.
This is illustrated in Figure 61.
Revision v3.2, January 2011
1. Write the data 0x62 to the I2C register I2CKeyMsb.
2. Write the data 0x9D to the I2C register I2CKeyLsb.
3. Write the data 0xA5 to the I2C register I2CSpmBaseAddr.
4. Write the data 0x5A to the I2C register I2CSpmBaseAddr.
1)
2)
3)
4)
S
SA
A
P
S
S
S
S
Figure 60
SA
SA
SA
SA
Low Power, Capacitive Button Touch and Proximity Controller
Figure 61:
: Start condition
: Slave address
: Slave acknowledge
: Stop condition
© 2011 Semtech Corp.
0
0
0
0
Simplified Diagram NvmCycle
A
A
A
A
NVM burn procedure
0xAC
0xAD
0x0E
0x0E
78
(8 sensors) with LED Drivers and Analog Output
A
A
A
A
0x9D
0xA5
0x5A
0x62
Terminate the I2C write by a STOP.
Terminate the I2C write by a STOP.
Terminate the I2C write by a STOP.
Terminate the I2C write by a STOP.
A
A
A
A
P
P
P
P
From master to slave
From slave to master
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DATASHEET
SX8661