HD64570 Datasheet, PDF (162/469 Pages) Hitachi Semiconductor – Serial Communications Adaptor

Bits 7−6: Reserved. These bits always read 0.
Bit 5 (SLOOP: Sending on Loop): Indicates MSCI data transmission status in bit synchronous
mode. This bit is set to 1 when the MSCI is transmitting data, and is cleared otherwise. This is a
read-only bit, and writing to it has no effect.
• Asynchronous/Byte synchronous mode
Reserved. This bit always reads 0.
• Bit synchronous mode
SLOOP = 0: Indicates that the MSCI is not transmitting data
SLOOP = 1: Indicates that the MSCI is transmitting data
Bit 4 (SRCH: Search Mode): Indicates whether or not the ADPLL is in search mode. This bit is
valid for transmission using FM codes in byte or bit synchronous mode. This is a read-only bit,
and writing to it has no effect. This bit is set to 1 by an enter search command or automatic search
mode initiated by two-clock missing detection.
• Asynchronous mode
Reserved. This bit always reads 0.
• Byte synchronous/Bit synchronous mode
SRCH = 0: Indicates that the ADPLL is not in search mode
SRCH = 1: Indicates that the ADPLL is in search mode
Bit 3 (CTS: CTS Input Line Status): Indicates the CTS line level. This is a read-only bit, and
writing to it has no effect.
• Asynchronous/Byte synchronous/Bit synchronous mode
CTS = 0: Indicates that the CTS input line is low
CTS = 1: Indicates that the CTS input line is high
Bit 2 (DCD: DCD Input Line Status): Indicates the DCD line level. This is a read-only bit, and
writing to it has no effect.
• Asynchronous/Byte synchronous/Bit synchronous mode
DCD = 0: Indicates that the DCD input line is low
DCD = 1: Indicates that the DCD input line is high
Bit 1 (TXENBL: TX Enable): Indicates whether the transmitter is enabled or disabled.
Transmitter enable/disable selection is performed by a command. This is a read-only bit, and
writing to it has no effect.
• Asynchronous/Byte synchronous/Bit synchronous mode
TXENBL = 0:Indicates that the transmitter is disabled
Rev. 0, 07/98, page 146 of 453