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HT66FM5440
Brushless DC Motor A/D Flash MCU
HT66FM5440
Brushless DC Motor A/D Flash MCU
IICC1 Register
Bit
7
6
5
4
3
2
1
0
Name
HCF
HAAS
HBB
HTX
TXAK
SRW
IAMWU
RXAK
R/W
R
R
R
R/W
R/W
R
R/W
R
POR
1
0
0
0
0
0
0
1
Bit 7
HCF
: I
2
C Bus data transfer completion flag
0: Data is being transferred
1: Completion of an 8-bit data transfer
The HCF flag is the data transfer flag. This flag will be zero when data is being
transferred. Upon completion of an 8-bit data transfer the flag will go high and an
interrupt will be generated.
Below is an example of the flow of a two-byte I
2
C data transfer.
First, I
2
C slave device receive a start signal from I
2
C master and then HCF bit is
automatically cleared to zero.
Second, I
2
C slave device finish receiving the 1st data byte and then HCF bit is
automatically set to one.
Third, user read the 1st data byte from IICD register by the application program and
then HCF bit is automatically cleared to zero.
Fourth, I
2
C slave device finish receiving the 2nd data byte and then HCF bit is
automatically set to one and so on.
Finally, I
2
C slave device receive a stop signal from I
2
C master and then HCF bit is
automatically set to one.
Bit 6
HAAS
: I
2
C Bus address match flag
0: Not address match
1: Address match
The HAAS flag is the address match flag. This flag is used to determine if the slave
device address is the same as the master transmit address. If the addresses match then
this bit will be high, if there is no match then the flag will be low.
Bit 5
HBB
: I
2
C Bus busy flag
0:
I
2
C Bus is not busy
1:
I
2
C Bus is busy
The HBB flag is the I
2
C busy flag. This flag will be "1" when the I
2
C bus is busy which
will occur when a START signal is detected. The flag will be set to "0" when the bus is
free which will occur when a STOP signal is detected.
Bit 4
HTX
: Select I
2
C slave device is transmitter or receiver
0: Slave device is the receiver
1: Slave device is the transmitter
Bit 3
TXAK
: I
2
C Bus transmit acknowledge flag
0: Slave send acknowledge flag
1: Slave do not send acknowledge flag
The TXAK bit is the transmit acknowledge flag. After the slave device receipt of 8-bits
of data, this bit will be transmitted to the bus on the 9th clock from the slave device.
The slave device must always set TXAK bit to "0" before further data is received.
Bit 2
SRW
: I
2
C Slave Read/Write flag
0: Slave device should be in receive mode
1: Slave device should be in transmit mode
The SRW flag is the I
2
C Slave Read/Write flag. This flag determines whether
the master device wishes to transmit or receive data from the I
2
C bus. When the
transmitted address and slave address is match, that is when the HAAS flag is set high,
the slave device will check the SRW flag to determine whether it should be in transmit
mode or receive mode. If the SRW flag is high, the master is requesting to read data
from the bus, so the slave device should be in transmit mode. When the SRW flag
is zero, the master will write data to the bus, therefore the slave device should be in
r
eceive mode to read this data.