HD64570 Datasheet, PDF (134/469 Pages) Hitachi Semiconductor – Serial Communications Adaptor

7
Async
—*
Byte sync
Bit sync HDLC
6
5
4
—* —* —*
UDRNC IDLC
3
2
1
BRK ^{— * — *}
— * _SYNCLD
—*
0
RTS
Read/Write
— — R/W R/W R/W R/W R/W R/W
Initial value
0
0
0
0
0
0
0
1
Send break
• Asynchronous
mode
0: Off
1: On (break send)
Idle state control
• Byte/Bit synchronous mode
0: Transmits a mark
1: Transmits an idle pattern
Request to send
0: Sets RTS low
1: Sets RTS high
Underrun state control
• Byte synchronous mode
0: Enters idle state immediately
1: Enters idle state after CRC transmission
• Bit synchronous mode
0: Enters idle state after aborting transmission
1: Enters idle state after FCS and flag transmission
SYN character
load enable
• Byte synchronous mode
0: Disable
1: Enable
Note: Reserved. These bits always read 0 and must be set to 0.
Rev. 0, 07/98, page 118 of 453