Rev. 1.10
86
November 26, 2019
Rev. 1.10
87
November 26, 2019
HT68FB240
USB Low Speed Flash MCU
Bit 1
SIMEN:
SIM Control
0: Disable
1: Enable
The bit is the overall on/off control for the SIM interface. When the SIMEN bit is
cleared to zero to disable the SIM interface, the SDI, SDO, SCK and
SCS
, or SDA
and SCL lines will be in a floating condition and the SIM operating current will be
reduced to a minimum value. When the bit is high the SIM interface is enabled. The
SIM configuration option must have first enabled the SIM interface for this bit to be
effective. If the SIM is configured to operate as an SPI interface via the SIM2~SIM0
bits, the contents of the SPI control registers will remain at the previous settings when
the SIMEN bit changes from low to high and should therefore be first initialised by
the application program. If the SIM is configured to operate as an I
2
C interface via the
SIM2~SIM0 bits and the SIMEN bit changes from low to high, the contents of the I
2
C
control bits such as HTX and TXAK will remain at the previous settings and should
therefore be first initialised by the application program while the relevant I
2
C flags
such as HCF, HAAS, HBB, SRW and RXAK will be set to their default states.
Bit 0
Unimplemented, read as "0"
SIMC1 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.
Bit 6
HAAS:
I
2
C Bus address match flag
0: Not address match
1: Address match
The HA
A
S 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.