HT68F20 Datasheet, PDF (137/210 Pages) Holtek Semiconductor Inc – Enhanced I/O Flash Type MCU 8-Bit MCU with EEPROM

HT68F20/HT68F30/HT68F40/HT68F50/HT68F60
· SIMC1 Register
Bit
Name
R/W
POR
7
HCF
R
1
6
HAAS
R
0
5
HBB
R
0
4
HTX
R/W
0
3
TXAK
R/W
0
2
SRW
R
0
1
IAMWU
R/W
0
0
RXAK
R
1
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
HCF: I²C 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.
HAAS: I²C Bus address match flag
0: Not address match
1: Address match
The HASS 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.
HBB: I²C Bus busy flag
0: I²C Bus is not busy
1: I²C Bus is busy
The HBB flag is the I²C busy flag. This flag will be ²1² when the I²C bus is busy which will
occur when a START signal is detected. The flag will be set to ²0² when the bus is free which will
occur when a STOP signal is detected.
HTX: Select I²C slave device is transmitter or receiver
0: Slave device is the receiver
1: Slave device is the transmitter
TXAK: I²C 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 ²0² before further data is received.
SRW: I²C 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 I²C Slave Read/Write flag. This flag determines whether the master
device wishes to transmit or receive data from the I²C 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 receive mode to read this data.
IAMWU: I²C Address Match Wake-up Control
0: Disable
1: Enable
This bit should be set to ²1² to enable I²C address match wake up from SLEEP or IDLE Mode.
RXAK: I²C Bus Receive acknowledge flag
0: Slave receive acknowledge flag
1: Slave do not receive acknowledge flag
The RXAK flag is the receiver acknowledge flag. When the RXAK flag is ²0², it means that a
acknowledge signal has been received at the 9th clock, after 8 bits of data have been
transmitted. When the slave device in the transmit mode, the slave device checks the RXAK flag
to determine if the master receiver wishes to receive the next byte. The slave transmitter will
therefore continue sending out data until the RXAK flag is ²1². When this occurs, the slave
transmitter will release the SDA line to allow the master to send a STOP signal to release the I²C
Bus.
Rev. 1.00
137
November 3, 2009