
M0A21/M0A23 Series
May 06, 2022
Page
598
of 746
Rev 1.02
M0
A21
/M
0
A
2
3
SE
RIES
TEC
H
NICAL
RE
FEREN
C
E
M
ANUAL
USCI Protocol Control Register
– I
2
C (UI2C_PROTCTL)
Register
Offset
R/W
Description
Reset Value
UI2C_PROTCTL
U0x5C
R/W
USCI Protocol Control Register
0x0000_0000
31
30
29
28
27
26
25
24
PROTEN
Reserved
TOCNT
23
22
21
20
19
18
17
16
TOCNT
15
14
13
12
11
10
9
8
Reserved
MONEN
SCLOUTEN
7
6
5
4
3
2
1
0
Reserved
PTRG
ADDR10EN
STA
STO
AA
GCFUNC
Bits
Description
[31]
PROTEN
I
2
C Protocol Enable Bit
0 = I
2
C Protocol Disabled.
1 = I
2
C Protocol Enabled.
[30:26]
Reserved
Reserved.
[25:16]
TOCNT
Time-out Clock Cycle
This bit field indicates how many clock cycle selected by TMCNTSRC (UI2C_BRGEN [5]) when each
interrupt flags are clear. The time-out is enable when TOCNT bigger than 0.
Note:
The
TMCNTSRC (UI2C_BRGEN [5]) must be set zero on I
2
C mode.
[15:10]
Reserved
Reserved.
[9]
MONEN
Monitor Mode Enable Bit
This bit enables monitor mode. In monitor mode the SDA output will be put in high impedance mode. This
prevents the I
2
C module from outputting data of any kind (including ACK) onto the I
2
C data bus.
0 = The monitor mode Disabled.
1 = The monitor mode Enabled.
Note:
Depending on the state of the SCLOUTEN bit, the SCL output may be also forced high, preventing
the module from having control over the I
2
C clock line.
[8]
SCLOUTEN
SCL Output Enable Bit
This bit enables monitor pulling SCL to low. This monitor will pull SCL to low until it has had time to respond
to an I
2
C interrupt.
0 = SCL output will be forced high due to open drain mechanism.
1 = I
2
C module may act as a slave peripheral just like in normal operation, the I
2
C holds the clock line low
until it has had time to clear I
2
C interrupt.
[7:6]
Reserved
Reserved.