Revision V1.0/October 2010

©2010 Semtech Corp.

SX8653

www.semtech.com

Page 21

ADVANCED COMMUNICATIONS & SENSING

DATASHEET

Multitouch 15kV ESD protection 4-Wire / 5-Wire

Resistive Touchscreen Controller with SPI Interface

9.3. SPI Host Commands

.The host can issue commands to change the operation mode or perform manual actions as defined in Table 14.

9.4. SPI implementation and multiple Read/Write

The SPI implemented on the SX8653 is set to the common setting CPOL=0 and CPHA=0 which means data are sampled

on the rising edge of the clock, and shifted on the falling one.

The default state of the clock when NCS gets asserted is low. If a host send a command while the system is busy, the

command is discarded.

The SPI protocol is designed to be able to do multiple read/write during a transaction. During one single operation, as long

as NCS stay asserted, the register address is automatically increased to allow sequential read/write (or sequential retrieval

of data). Between each different operation though (READ/WRITE/READCHAN), the communication should be restarted.

This is described in Figure 18.

command name

CR(7:0)

Function

7

6

5

4

3

2

1

0

SELECT(CHAN)

1

0

0

0

x

CHAN(2:0)

Bias channel (see Table 13 for CHAN)

CONVERT(CHAN)

1

0

0

1

x

CHAN(2:0)

Bias channel (see Table 13 for CHAN)

MANAUTO

1

0

1

1

x

x

x

x

Enter manual or automatic mode.

PENDET

1

1

0

0

x

x

x

x

Enter pen detect mode.

PENTRG

1

1

1

0

x

x

x

x

Enter pen trigger mode.

Table 14.

Host Commands