I2C Registers
Table 21-16. I2C_WE Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
9
AAS_WE
R/W
0h
Address as slave IRQ wakeup enable.
This read/write bit is used to enable or disable wakeup signal
generation when I2C module is in idle mode, and external master
addresses the I2C module as a slave.
This allows for the module to inform the CPU that it can check which
of the own addresses was used by the external master to access the
I2C core.
0x0 = Addressed as slave wakeup disabled
0x1 = Addressed as slave wakeup enabled
8
BF_WE
R/W
0h
Bus free IRQ wakeup enable.
This read/write bit is used to enable or disable wakeup signal
generation when I2C module is in idle mode and the I2C bus
became free.
This allows for the module to inform the CPU that it can initiate its
own transfer on the I2C line.
0x0 = Bus Free wakeup disabled
0x1 = Bus Free wakeup enabled
7
Reserved
R
0h
6
STC_WE
R/W
0h
Start condition IRQ wakeup set.
This read/write bit is used to enable or disable wakeup signal
generation when I2C module is in idle mode (with the functional
clock inactive) and a possible start condition is detected on the I2C
line.
The STC WakeUp is generated only if the I2C_SYSC.ClockActivity
field indicates that the functional clock can be disabled.
Note that if the functional clock is not active, the start condition is
asynchronously detected (no filtering and synchronization is used).
For this reason, it is possible that the signalized start condition to be
a glitch.
If the functional clock cannot be disabled (I2C_SYSC.ClockActivity =
10 or 11), the programmer should not enable this wakeup, since the
module has other synchronously detected WakeUp event that might
be used to exit from idle mode, only if the detected transfer is
accessing the I2C module.
0x0 = Start condition wakeup disabled
0x1 = Start condition wakeup enabled
5
GC_WE
R/W
0h
General call IRQ wakeup enable.
This read/write bit is used to enable or disable wakeup signal
generation when I2C module is in idle mode and a general call is
received on I2C line.
0x0 = General call wakeup disabled
0x1 = General call wakeup enabled
4
Reserved
R
0h
3
DRDY_WE
R/W
0h
Receive/Transmit data ready IRQ wakeup enable.
This read/write bit is used to enable or disable wakeup signal
generation when I2C module is involved into a long transfer and no
more registers accesses are performed on the interface (for example
module are set in F/S I2C master transmitter mode and FIFO is full).
If in the middle of such a transaction, the FIFO buffer needs more
data to be transferred, CPU must be informed to write (in case of
transmitter mode) or read (if receiver mode) in/from the FIFO.
0x0 = Transmit/receive data ready wakeup disabled
0x1 = Transmit/receive data ready wakeup enabled
2
ARDY_WE
R/W
0h
Register access ready IRQ wakeup enable.
This read/write bit is used to enable or disable wakeup signal
generation when I2C module is involved into a long transfer and no
more registers accesses are performed on the interface (for example
the module is set in F/S I2C master transmitter mode and FIFO is
full).
If the current transaction is finished, the module needs to inform
CPU about transmission completion.
0x0 = Register access ready wakeup disabled
0x1 = Register access ready wakeup enabled
3734
I2C
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated