Rev. 1.60
184
August 20, 2019
Rev. 1.60
185
August 20, 2019
BS66F340/BS66F350/BS66F360/BS66F370
Touch A/D Flash MCU with LED Driver
BS66F340/BS66F350/BS66F360/BS66F370
Touch A/D Flash MCU with LED Driver
Address Detect Mode
Setting the Address Detect function enable control bit, ADDEN, in the UCR2 register, enables this
special function. If this bit is set to 1, then an additional qualifier will be placed on the generation
of a Receiver Data Available interrupt, which is requested by the RXIF flag. If the ADDEN bit
is equal to 1, then when the data is available, an interrupt will only be generated, if the highest
received bit has a high value. Note that the related interrupt enable control bit and the EMI bit of the
microcontroller must also be enabled for correct interrupt generation. The highest address bit is the
9
th
bit if the bit BNO=1 or the 8
th
bit if the bit BNO=0. If the highest bit is high, then the received
word will be defined as an address rather than data. A Data Available interrupt will be generated
every time the last bit of the received word is set. If the ADDEN bit is equal to 0, then a Receive
Data Available interrupt will be generated each time the RXIF flag is set, irrespective of the data last
but status. The address detection and parity functions are mutually exclusive functions. Therefore, if
the address detect function is enabled, then to ensure correct operation, the parity function should be
disabled by resetting the parity function enable bit PREN to zero.
ADDEN
Bit 9 if BNO=1
Bit 8 if BNO=0
UART Interrupt
Generated
0
0
√
1
√
1
0
X
1
√
ADDEN Bit Function
UART Power Down and Wake-up
When the MCU system clock is switched off, the UART will cease to function. If the MCU executes
the "HALT" instruction and switches off the system clock while a transmission is still in progress,
then the transmission will be paused until the UART clock source derived from the microcontroller
is activated. In a similar way, if the MCU executes the "HALT" instruction and switches off the
system clock while receiving data, then the reception of data will likewise be paused. When the
MCU enters the IDLE or SLEEP Mode, note that the USR, UCR1, UCR2, transmit and receive
registers, as well as the BRG register will not be affected. It is recommended to make sure first that
the UART data transmission or reception has been finished before the microcontroller enters the
IDLE or SLEEP mode.
The UART function contains a receiver RX pin wake-up function, which is enabled or disabled
by the WAKE bit in the UCR2 register. If this bit, along with the UART enable bit, UARTEN, the
receiver enable bit, RXEN and the receiver interrupt bit, RIE, are all set before the MCU enters the
IDLE0 or SLEEP Mode, then a falling edge on the RX pin will wake up the MCU from the IDLE0
or SLEEP Mode. Note that as it takes certain system clock cycles after a wake-up, before normal
microcontroller operation resumes, any data received during this time on the RX pin will be ignored.
For a UART wake-up interrupt to occur, in addition to the bits for the wake-up being set, the global
interrupt enable bit, EMI, and the UART interrupt enable bit, URE, must be set. If the EMI and URE
bits are not set then only a wake up event will occur and no interrupt will be generated. Note also
that as it takes certain system clock cycles after a wake-up before normal microcontroller resumes,
the UART interrupt will not be generated until after this time has elapsed.