sx8675iwltrt Semtech Corporation, sx8675iwltrt Datasheet - Page 41

• Manufacturer Part Number: sx8675iwltrt
• Description: Haptics Enabled Multitouch 4/5-wire Resistive Touchscreen Controller With Proximity Sensing
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & SENSING
8
8.1
The purpose of the NIRQ pin is to indicate to the host (via a falling edge) when any of the events considered
being time-critical has occurred. Non time-critical events can be monitored via I2C by reading regularly the
relevant status bits.
8.2
8.2.1
This register allows the host to decide which interrupt sources he wants to monitor via the NIRQ signal. Please
note that a reset event will always trigger NIRQ falling edge whatever RegIrqMsk (Cf § 10)
8.2.2
This register indicates to the host which of the interrupt sources triggered the NIRQ signal. More than one bit
can be set if several events occurred before host reads the register.
If bit 3 is OFF, reading the register will clear it together with releasing NIRQ signal. Else, if bit 3 is ON and we are
in MAN or PENTRG mode, both register and NIRQ will be cleared only once all channel data have been read. All
ADC related operations (touch conversion, proximity conversion, pen detection) are stopped as long as all
channel data have not been read.
Bits which RegIrqMsk corresponding bits are set to 0 (ie source not monitored) will always read 0 even if the
event actually occurred.
8.2.3
This register regroups all status information of the chip and is used by all interrupt sources to detect the relevant
events. For each bit, if the relevant block is ON its value is constantly updated, else it is set to 0. This register
update is completely independent from RegIrqMsk.
8.3
Rev 1 – 25
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I
NTERRUPT
Introduction
Registers Overview
Host Procedure
RegIrqMsk
RegIrqSrc
RegStat
Configure the different blocks parameters(TS, Proximity, etc)
Program RegIrqMsk to start monitoring what is considered to be “time-critical” events
Enable the blocks to start RegStat update and hence NIRQ process.
Each time NIRQ falling edge occurs, read RegIrqSrc to know which “time-critical” event occurred (+ read
channel data if relevant)
In addition, RegStat can be read anytime to get the whole picture including also what is considered to be
“non time-critical” information.
th
July 2011
(NIRQ)
Resistive Touchscreen Controller with Proximity Sensing
41
SX8674/SX8675/SX8676
Haptics Enabled Multitouch 4/5-Wire
www.semtech.com