HD64570 Datasheet, PDF (140/469 Pages) Hitachi Semiconductor – Serial Communications Adaptor

Bit 7: Reserved. This bit always reads 0 and must be set to 0.
Bits 6–4 (TXCS2–TXCS0: Transmit Clock Source): Specify the transmit clock source.
• Asynchronous/Byte synchronous/Bit synchronous mode
TXCS2–TXCS0 = 0, 0, 0: Specifies the TXC line input as the transmit clock.
TXCS2–TXCS0 = 1, 0, 0: Specifies the internal BRG output as the transmit clock, which
is output from the TXC line.
TXCS2–TXCS0 = 1, 1, 0: Specifies the receive clock as the transmit clock. This setting
is used for using the clock extracted by the ADPLL as the transmit clock.
Other settings:
Reserved.
Bits 3–0 (TXBR3–TXBR0: Transmitter Baud Rate): Used in conjunction with the time
constant register (TMC) to specify the baud rate of the baud rate generator in the transmitter. For
details, see section 5.6, Baud Rate Generator.
• Asynchronous /Byte synchronous/Bit synchronous mode
TXBR3–TXBR0 = 0, 0, 0, 0: Division ratio = 1/1
TXBR3–TXBR0 = 0, 0, 0, 1: Division ratio = 1/2
TXBR3–TXBR0 = 0, 0, 1, 0: Division ratio = 1/4
TXBR3–TXBR0 = 0, 0, 1, 1: Division ratio = 1/8
TXBR3–TXBR0 = 0, 1, 0, 0: Division ratio = 1/16
TXBR3–TXBR0 = 0, 1, 0, 1: Division ratio = 1/32
TXBR3–TXBR0 = 0, 1, 1, 0: Division ratio = 1/64
TXBR3–TXBR0 = 0, 1, 1, 1: Division ratio = 1/128
TXBR3–TXBR0 = 1, 0, 0, 0: Division ratio = 1/256
TXBR3–TXBR0 = 1, 0, 0, 1: Division ratio = 1/512
TXBR3–TXBR0 = 1, 0, 1, 0: Reserved
→→
TXBR3–TXBR0 = 1, 1, 1, 1: Reserved
Rev. 0, 07/98, page 124 of 453