HD64570 HITACHI [Hitachi Semiconductor], HD64570 Datasheet - Page 134

• Manufacturer Part Number: HD64570
• Description: Serial Communications Adaptor
• Manufacturer: HITACHI [Hitachi Semiconductor]

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