Data Sheet

537
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
27.8.1 I
2
C Slave Register Description
27.8.1.1 Control A
Name: CTRLA
Offset: 0x00
Reset: 0x00000000
Property: Write-Protected, Enable-Protected, Write-Synchronized
z Bit 31 – Reserved
This bit is unused and reserved for future use. For compatibility with future devices, always write this bit to zero
when this register is written. This bit will always return zero when read.
z Bit 30 – LOWTOUT: SCL Low Time-Out
This bit enables the SCL low time-out. If SCL is held low for 25ms-35ms, the slave will release its clock hold, if
enabled, and reset the internal state machine. Any interrupts set at the time of time-out will remain set.
0: Time-out disabled.
1: Time-out enabled.
z Bits 29:28 – Reserved
These bits are unused and reserved for future use. For compatibility with future devices, always write these bits to
zero when this register is written. These bits will always return zero when read.
z Bit 27– SCLSM: SCL Clock Stretch Mode
This bit controls when SCL will be stretch for software interaction.
0: SCL stretch according to Figure 27-7
Bit3130292827262524
LOWTOUT SCLSM SPEED[1:0]
Access R R/W R R R/W R R/W R/W
Reset00000000
Bit2322212019181716
SEXTTOEN
SDAHOLD[1:0] PINOUT
Access R/W R R/W R/W R R R R/W
Reset00000000
Bit 15 14 13 12 11 10 9 8
AccessRRRRRRRR
Reset00000000
Bit76543210
RUNSTDBY
MODE[2:0]=100 ENABLE SWRST
Access R/W R R R/W R/W R/W R/W R/W
Reset00000000