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M0A21/M0A23 Series
May 06, 2022
Page
602
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 Status Register
– I
2
C (UI2C_PROTSTS)
Register
Offset
R/W
Description
Reset Value
UI2C_PROTSTS
U0x64
R/W
USCI Protocol Status Register
0x0000_0000
31
30
29
28
27
26
25
24
Reserved
23
22
21
20
19
18
17
16
Reserved
ERRARBLO
BUSHANG
WRSTSWK
WKAKDONE
15
14
13
12
11
10
9
8
SLAREAD
SLASEL
ACKIF
ERRIF
ARBLOIF
NACKIF
STORIF
STARIF
7
6
5
4
3
2
1
0
Reserved
ONBUSY
TOIF
Reserved
Bits
Description
[31:20]
Reserved
Reserved.
[19]
ERRARBLO
Error Arbitration Lost
This bit indicates
bus arbitration lost due to bigger noise which is can’t be filtered by input processor. The
I
2
C can send start condition when ERRARBLO is set. Thus this bit doesn’t be cared on slave mode.
0 = The bus is normal status for transmission.
1 = The bus is error arbitration lost status for transmission.
Note:
This bit has no interrupt signal, and it will be cleared automatically by hardware when a START
condition is present.
[18]
BUSHANG
Bus Hang-up
This bit indicates bus hang-up status. There is 4-bit counter count when SCL hold high and refer
f
SAMP_CLK
. The hang-up counter will count to overflow and set this bit when SDA is low. The counter will be
reset by falling edge of SCL signal.
0 = The bus is normal status for transmission.
1 = The bus is hang-up status for transmission.
Note:
This bit has no interrupt signal, and it will be cleared automatically by hardware when a START
condition is present.
[17]
WRSTSWK
Read/Write Status Bit in Address Wake-up Frame
0 = Write command be record on the address match wake-up frame.
1 = Read command be record on the address match wake-up frame.
[16]
WKAKDONE
Wake-up Address Frame Acknowledge Bit Done
0 = The ACK bit cycle of address match frame isn’t done.
1 = The ACK bit cycle of address match frame is done in power-down.
Note:
This bit can’t clear when WKF is not be clear.
[15]
SLAREAD
Slave Read Request Status
This bit indicates that a slave read request has been detected.
0 = A slave R/W bit is 1 has not been detected.
1 = A slave R/W bit is 1 has been detected.
Note:
This bit has no interrupt signal, and it will be cleared automatically by hardware.