CD2401 Intel, CD2401 Datasheet - Page 107

• Manufacturer Part Number: CD2401
• Description: Multi-protocol Communications Controller
• Manufacturer: Intel

Datasheet
Register Name: COR6
Register Description: Channel Option 6
Default Value: x’00
Access: Byte Read/Write
Bit 7
Note: This feature is not available in revisions prior to Revision ‘H’.
COR6 — Bisync Mode
In Bisynchronous mode, this register provides a frame-termination method for a receive character
other than the one already defined in the bisynchronous specification. When an initialize channel
command in the CCR is processed, COR6 is set to the value of DLE (hex 10); this deactivates the
function because DLE processing is always performed before a match with COR6 is performed.
Following the completion of the initialize channel command, the user can program COR6 to any
character value where frame termination is required.
One use of this might be to terminate non-transparent frames where the termination character has
been corrupted. If the idle line character (hex FF in 8-bit mode, hex 7F in 7-bit mode) is
programmed in COR6 when a normal termination character is corrupted (that is, ETX hex 03 is
changed to hex 07), the BCC is received as data and the idle line condition causes the frame to
terminate. The idle line character is the last character in the frame. No attempt is made to perform a
CRC on the receive data under these conditions.
Bit 6
1.When ParMrk = 1 and ParInt = 1, each occurrence of FF hex in the datastream is preceded
ParMrk
Bit 5
1
by FF hex to distinguish it from a parity error sequence.
0
0
0
0
1
1
1
1
Special Frame Termination Character
INPCK
0
0
1
1
0
0
1
1
Bit 4
Multi-Protocol Communications Controller — CD2401
ParInt
0
1
0
1
0
1
0
1
Bit 3
Generated an exception interrupt.
Translated to a NULL character.
Ignore error; character passed on as Good Data.
Discard error character.
Reserved
Translate to a sequence of FF NULL and the error
character, pass on as Good Data.
Reserved
Reserved
Bit 2
Function
Motorola Hex Address: x’18
Bit 1
Intel Hex Address: x’1B
Bit 0
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