SX8650 Datasheet, PDF (31/56 Pages) Semtech Corporation – World’s Lowest Power & Smallest Footprint 4-wire Resistive Touchscreen Controller with 15kV ESD

SX8650
World’s Lowest Power & Smallest Footprint 4-wire
Resistive Touchscreen Controller with 15kV ESD
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
4.6.3. I2C Read Registers
The format for incremental I2C read for registers is given in Figure 29. The read has to start with a write of the read
address.
After the start condition [S], the SX8650 Slave Address (SA) is sent, followed by an eighth bit (W=‘0’) indicating a Write.
The SX8650 then Acknowledges [A] that it is being addressed, and the host responds with a 8-bit CR Data consisting of
‘010’ followed by the Register Address (RA). The SX8650 responds with an Acknowledge [A] and the host sends the
Repeated Start Condition [Sr]. Once again, the SX8650 Slave Address (SA) is sent, followed by an eighth bit (R=‘1’)
indicating a Read.
The SX8650 responds with an Acknowledge [A] and the read Data byte (RD0). If the host needs to read more data it will
acknowledge [A] and the SX8650 will send the next read byte (RD1). This sequence can be repeated until the host
terminates with a NACK [N] followed by a stop [P].
S SA W A CR A Sr SA R A RD0 A RD1 A
RDn N P
S:
Sr:
SA:
W:
R:
A:
N:
CR:
RDn:
P:
Start Condition
Repeated Start Condition
SX8650 Slave Address(7:1)
'0'
'1'
ACKnowledge
Not ACKnowledge (terminating read stream)
'010' + Register Address(4:0)
Read Data byte(7:0), 0...n
Stop Condition
Optional
From Host to SX8650
From SX8650 to Host
Figure 29. I2C read registers
The I2C read register format of Figure 29 is maintained until the Stop Condition. After the Stop Condition the SX8650 is
performing succeeding reads by the compact read format of the I2C read channels described in the next section.
No clock stretching will occur for the I2C read registers.
ACS Revision V2.15/October 2009
©2009 Semtech Corp.
Page 30
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