Datasheet

78K0/Ix2 CHAPTER 14 SERIAL INTERFACE UART6/DALI
R01UH0010EJ0500 Rev.5.00 438
Feb 28, 2012
(4) UART transmission status register 6 (ASIF6)
This register indicates the status of transmission by serial interface UART6. It includes two status flag bits (TXBF6
and TXSF6).
Transmission can be continued without disruption even during an interrupt period, by writing the next data to the
TXB6 register after data has been transferred from the TXB6 register to the TXS6 register.
This register is read-only by an 8-bit memory manipulation instruction.
Reset signal generation, or clearing bit 7 (POWER6) or bit 6 (TXE6) of ASIM6 to 0 clears this register to 00H.
Caution ASICL6 is not used in DALI mode (UADLSEL = 1). The read value of the TXBF6, TXSF6 bit is 0 in
DALI mode.
Figure 14-8. Format of UART Transmission Status Register 6 (ASIF6)
Address: FF55H After reset: 00H R
Symbol 7 6 5 4 3 2 1 0
ASIF6 0 0 0 0 0 0 TXBF6 TXSF6
TXBF6 Transmit buffer data flag
0 If POWER6 = 0 or TXE6 = 0, or if data is transferred to UART/DALI transmit shift register 6 (TXS6)
1 If data is written to transmit buffer register 6 (TXB6) (if data exists in TXB6)
TXSF6 Transmit shift register data flag
0
If POWER6 = 0 or TXE6 = 0, or if the next data is not transferred from transmit buffer register 6
(TXB6) after completion of transfer
1 If data is transferred from transmit buffer register 6 (TXB6) (if data transmission is in progress)
Cautions 1. To transmit data continuously, write the first transmit data (first byte) to the TXB6 register. Be
sure to check that the TXBF6 flag is “0”. If so, write the next transmit data (second byte) to the
TXB6 register. If data is written to the TXB6 register while the TXBF6 flag is “1”, the transmit data
cannot be guaranteed.
2. To initialize the transmission unit upon completion of continuous transmission, be sure to check
that the TXSF6 flag is “0” after generation of the transmission completion interrupt, and then
execute initialization. If initialization is executed while the TXSF6 flag is “1”, the transmit data
cannot be guaranteed.
(5) Clock selection register 6 (CKSR6)
This register selects the base clock of serial interface UART6/DALI.
CKSR6 can be set by an 8-bit memory manipulation instruction.
Reset signal generation sets this register to 00H.
Remark CKSR6 can be refreshed (the same value is written) by software during a communication operation (when
bits 7 and 6 (POWER6, TXE6) of ASIM6 = 1 or bits 7 and 5 (POWER6, RXE6) of ASIM6 = 1).