BAT32G1x9 user manual | Chapter 20 Serial interface IICA
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Rev.1.02
Figure 20-25: Communication appointment steps
stop interrupt request
STTn=1
define communication
preservation
Wait
MSTSn=0
?
release communication
preserve
IICAn=xxH
enable interrupt request
Yes
(generate start condition)
( communication
preservation )
note2
set STTn flag to '1'
(communication preserve)
define as in communication preserve state.
( to configure and set user flag of any RAM)
ensure wait time via software.
Note 1
.
confirm communication preservation
clear user flag
Write IICAn
。
No
Note: 1.
The waiting time is as follows:
(IICWLn
setpoint
+ IICWHn
setpoint
+4)/f
MCK
+t
F
×
2
2. Write the IICA
shift register
n
(IICAn) by stopping the conditional interrupt request while the communication
appointment is running.
Remarks: 1. STTn :
Bit1
of
IICA
control register
n0
(IICCTLn0
).
MSTSn :
Bit7
of
the IICA
status register
n
(IICSn
).
IICAn
:
IICA
shift register
n
IICWLn
:
IICA
low-level width setting register
n
IICWHn:
IICA
high level width setting register
n
t
F
:
The descent time of the
SDAAn
signal and
the
SCLAn
signal
f
MC
:
IICA
operating clock frequency
2. n=0.1
(2) Case where the communication appointment function is prohibited (bit0 (IICRSVn) of the IICA flag register
n (IICFn) = 1)
During bus communication, if you are not participating in this communication, the bit1 (STTn) of the IICA control
register n0 (IICCTLn0) is placed
"1" rejects the request and does not generate a start condition. The non-joining bus at this time includes the
following two states:
•
When the outcome of the arbitration is neither the master nor the slave
•
Does not run as a slave after receiving the extension code (bit6 (LRELn) of the IICCTLn0 register is set to
"1" without returning a reply, and the bus is released after exiting communication).