Programmable Four-Channel Communications Controller
—
CD2481
Datasheet
135
COR6
—
Programmable Sync Mode
In Programmable Sync (CMR mode 0x08) mode, this register defines the SYN1 character, to be
used to find character synchronization within the receive data stream. Unused bits must be zero.
9.2.8
Channel Option Register 7 (COR7)
Async Mode
CR is defined as 0D hex, NL as 0A hex and NULL as 00 hex.
Bit 7
IStrip
–
when this bit is set, the most-significant bit of receive characters is stripped,
leaving 7-bit characters. IStrip is applied after all other character processing, but
before special character processing.
Bit 6
LNext
–
this bit enables the LNext option
0 = All receive characters are processed for special character detection.
1 = The character following the LNext character is not processed for special charac-
ter matching or flow control.
This provides a mechanism to transfer flow control and special characters as normal
data, without invoking flow control action in the CD2481, and without generating
special interrupts. The LNext character is defined in the LNXT register, and when
processed, is always passed to the host CPU as normal data.
Bit 5
Flow control on error characters
0 = Characters received with an error are not processed for special character/flow
control matching.
1 = All receive characters, even those with errors, are processed for special charac-
ter/flow control processing.
Bits 4:2
Reserved
–
must be zero.
Register Name: COR6
Register Description: Channel Option 6
Default Value: x
’
00
Access: Byte Read/Write
Intel Hex Address: x
’
1B
Motorola Hex Address: x
’
18
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
SYN1 Character
Register Name: COR7
Register Description: Channel Option Register 7
Default Value: x
’
00
Access: Byte Read/Write
Intel Hex Address: x
’
04
Motorola Hex Address: x
’
07
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
IStrip
LNE
FCErr
0
0
0
ONLCR
OCRNL