Value
Name
Description
0x0
DIS
Disabled
0x1
55US
5-6 SCL cycle time-out (50-60µs)
0x2
105US
10-11 SCL cycle time-out (100-110µs)
0x3
205US
20-21 SCL cycle time-out (200-210µs)
Bit 27 – SCLSM: SCL Clock Stretch Mode
This bit controls when SCL will be stretched for software interaction.
This bit is not synchronized.
Value
Description
0
SCL stretch according to
1
SCL stretch only after ACK bit,
Bits 25:24 – SPEED[1:0]: Transfer Speed
These bits define bus speed.
These bits are not synchronized.
Value
Description
0x0
Standard-mode (Sm) up to 100 kHz and Fast-mode (Fm) up to 400 kHz
0x1
Fast-mode Plus (Fm+) up to 1 MHz
0x2
High-speed mode (Hs-mode) up to 3.4 MHz
0x3
Reserved
Bit 23 – SEXTTOEN: Slave SCL Low Extend Time-Out
This bit enables the slave SCL low extend time-out. If SCL is cumulatively held low for greater than 25ms
from the initial START to a STOP, the master will release its clock hold if enabled, and complete the
current transaction. A STOP will automatically be transmitted.
SB or MB will be set as normal, but CLKHOLD will be release. The MEXTTOUT and BUSERR status bits
will be set.
This bit is not synchronized.
Value
Description
0
Time-out disabled
1
Time-out enabled
Bit 22 – MEXTTOEN: Master SCL Low Extend Time-Out
This bit enables the master SCL low extend time-out. If SCL is cumulatively held low for greater than
10ms from START-to-ACK, ACK-to-ACK, or ACK-to-STOP the master will release its clock hold if
enabled, and complete the current transaction. A STOP will automatically be transmitted.
SB or MB will be set as normal, but CLKHOLD will be released. The MEXTTOUT and BUSERR status
bits will be set.
This bit is not synchronized.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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