Holtek HT66F488 Manual page 123

HT66F488/HT66F489
A/D Flash MCU with EEPROM
SIMEN: SIM Control
Bit 1
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 lose their SPI or I
reduced to a minimum value. When the bit is high the SIM interface is enabled. 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
bits and the SIMEN bit changes from low to high, the contents of the I
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
HAAS, HBB, SRW and RXAK will be set to their default states.
Bit 0 SPIICF: SPI Incompleted Flag
0: SPI incompleted is not occurred
1: SPI incompleted is occurred
The SPIICF bit is determined by SCS pin. When SCS pin is set to "1", it will clear the
SPI counter. Meanwhile, the interrupt is occurred, if slave device didn't complete data
received, then the incompleted flag, SPIICF, is set to"1".
SIMC1 Register
Bit
�a�e HCF
R/W R
POR
HCF: I
Bit 7
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
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
0: I
1: I
The HBB flag is the I
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.
HTX: Select I
Bit 4
0: Slave device is the receiver
1: Slave device is the transmitter
Rev. 1.21
7 6 5
HAAS HBB
R R
1 � �
C Bus data transfer completion flag
2
C Bus address match flag
2
C Bus busy flag
2
C Bus is not busy
2
C Bus is busy
2
C busy flag. This flag will be "1" when the I
2
C slave device is transmitter or receiver
2
123
C function and the SIM operating current will be
2
C interface via the SIM2~SIM0
2
C flags such as HCF,
2
4 3 2
HTX TXAK SRW
R/W R/W R
� � �
C control bits
2
1 0
IAMWU RXAK
R/W R
� 1
C bus is busy
2
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