HD64570 Datasheet, PDF (138/469 Pages) Hitachi Semiconductor – Serial Communications Adaptor

Bit 7: Reserved. This bit always reads 0 and must be set to 0.
Bits 6−4 (RXCS2−RXCS0: Receive Clock Source): Specify the receive clock source.
• Asynchronous/Byte synchronous/Bit synchronous mode
RXCS2−RXCS0 = 0, 0, 0: Specifies the RXC line input as the receive clock. The noise
suppressor does not function for the receive clock and receive data.
RXCS2−RXCS0 = 0, 1, 0: Specifies the RXC line input as the receive clock. The noise
suppressor of the ADPLL functions for the receive clock and receive data.
RXCS2−RXCS0 = 1, 0, 0: Specifies the internal BRG output as the receive clock, which
is output from the RXC line.
RXCS2−RXCS0 = 1, 1, 0: Specifies the clock extracted by the ADPLL as the receive
clock, which is output from the RXC line. The BRG output serves as the ADPLL operating
clock, and the noise suppressor functions for the receive data.
RXCS2−RXCS0 = 1, 1, 1: Specifies the clock extracted by the ADPLL as the receive
clock. The RXC line input serves as the ADPLL operating clock, and the noise suppressor
functions for the receive data.
Other settings:
Reserved.
Bits 3−0 (RXBR3−RXBR0: Receiver Baud Rate): Used in conjunction with the time constant
register (TMC) to specify the baud rate of the baud rate generator in the receiver. For details, see
section 5.6, Baud Rate Generator.
• Asynchronous/Byte synchronous/Bit synchronous mode
RXBR3–RXBR0 = 0, 0, 0, 0: Division ratio = 1/1
RXBR3–RXBR0 = 0, 0, 0, 1: Division ratio = 1/2
RXBR3–RXBR0 = 0, 0, 1, 0: Division ratio = 1/4
RXBR3–RXBR0 = 0, 0, 1, 1: Division ratio = 1/8
RXBR3–RXBR0 = 0, 1, 0, 0: Division ratio = 1/16
RXBR3–RXBR0 = 0, 1, 0, 1: Division ratio = 1/32
RXBR3–RXBR0 = 0, 1, 1, 0: Division ratio = 1/64
RXBR3–RXBR0 = 0, 1, 1, 1: Division ratio = 1/128
RXBR3–RXBR0 = 1, 0, 0, 0: Division ratio = 1/256
RXBR3–RXBR0 = 1, 0, 0, 1: Division ratio = 1/512
RXBR3–RXBR0 = 1, 0, 1, 0: Reserved
→→
RXBR3–RXBR0 = 1, 1, 1, 1: Reserved
Rev. 0, 07/98, page 122 of 453