34.10.1. Control A
Name:
CTRLA
Offset:
0x00
Reset:
0x00000000
Property:
PAC Write-Protection, Enable-Protected, Write-Synchronized
Bit
31
30
29
28
27
26
25
24
LOWTOUT
INACTOUT[1:0]
SCLSM
SPEED[1:0]
Access
R/W
R/W
R/W
R/W
R/W
R/W
Reset
0
0
0
0
0
0
Bit
23
22
21
20
19
18
17
16
SEXTTOEN
MEXTTOEN
SDAHOLD[1:0]
PINOUT
Access
R/W
R/W
R/W
R/W
R/W
Reset
0
0
0
0
0
Bit
15
14
13
12
11
10
9
8
Access
Reset
Bit
7
6
5
4
3
2
1
0
RUNSTDBY
MODE[2:0]
ENABLE
SWRST
Access
R/W
R/W
R/W
R/W
R/W
R/W
Reset
0
0
0
0
0
0
Bit 30 – LOWTOUT: SCL Low Time-Out
This bit enables the SCL low time-out. If SCL is held low for 25ms-35ms, the master will release its clock
hold, if enabled, and complete the current transaction. A stop condition will automatically be transmitted.
INTFLAG.SB or INTFLAG.MB will be set as normal, but the clock hold will be released. The
STATUS.LOWTOUT and STATUS.BUSERR status bits will be set.
This bit is not synchronized.
Value
Description
0
Time-out disabled.
1
Time-out enabled.
Bits 29:28 – INACTOUT[1:0]: Inactive Time-Out
If the inactive bus time-out is enabled and the bus is inactive for longer than the time-out setting, the bus
state logic will be set to idle. An inactive bus arise when either an I
2
C master or slave is holding the SCL
low.
Enabling this option is necessary for SMBus compatibility, but can also be used in a non-SMBus set-up.
Calculated time-out periods are based on a 100kHz baud rate.
These bits are not synchronized.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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