SX8663 datasheet(19/64 Pages) SEMTECH

19 / 64 page

ADVANCED COMMUNICATIONS & SENSING

Rev5 4

th August 2011

www.semtech.com

SX8663

Capacitive Button Matrix (up to 36) and Proximity Controller

with Individual LED Drivers and Buzzer Output

In case the application needs different settings than the QSM settings then the SX8663 can be setup and/or

programmed over the I2C interface.

The configuration parameters of the SX8663 can be stored in the Multiple Time Programmable (MTP) Non

Volatile Memory (NVM). The NVM contains all those parameters that are defined and stable for the application.

Examples are the number of sensors enabled, sensitivity, active and Doze scan period. The details of these

parameters are described in the next chapters.

At power up the SX8663 checks if the NVM contains valid data. In that case the configuration parameter source

becomes the NVM. If the NVM is empty or non-valid then the configuration source becomes the QSM. In the next

step the SX8663 copies the configuration parameter source into the Shadow Parameter Memory (SPM). The

SX8663 is operational and uses the configuration parameters of the SPM.

During power down or reset event the SPM loses all content. It will automatically be reloaded following power up

or at the end of the reset event.

The host will interface with the SX8663 through the I2C bus and the analog output interface.

The I2C of the SX8663 consists of 16 registers. Some of these I2C registers are used to read the status and

information of the buttons. Other I2C registers allow the host to take control of the SX8663. The host can e.g.

decide to change the operation mode from active mode to Doze mode or go into sleep (according Figure 7).

Two additional modes allow the host to have an access to the SPM or indirect access to the NVM.

These modes are required during development, can be used in real time or in-field programming.

Figure 15 shows the Host SPM mode. In this mode the host can decide to overwrite the SPM. This is useful

during the development phases of the application where the configuration parameters are not yet fully defined and

as well during the operation of the application if some parameters need small deviations from the QSM or NVM

content.

Figure 15

Host SPM mode

The content of the SPM remains valid as long as the SX8663 is powered. After a power down the host needs to

re-write the SPM at the next power-up.

Figure 16 shows the Host NVM mode. In this mode the host will be able to write the NVM.

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