CD2481 Datasheet, PDF (154/222 Pages) Intel Corporation – Programmable Four-Channel Communications Controller

CD2481 — Programmable Four-Channel Communications Controller
Bit 2
Tx flag
0 = Currently not transmitting flag
1 = Currently transmitting flag
Bit 1
Tx frame
0 = Currently not transmitting frame
1 = Currently transmitting frame
Bit 0
Tx mark
0 = Currently not transmitting continuous ones
1 = Currently transmitting continuous ones
CSR –Bisynchronous Mode
Register Name: CSR
Register Description: Channel Status Register
Default Value: x’00
Access: Byte Read/Write
Bit 7
Bit 6
Bit 5
Bit 4
RxEn
RxITB
RxFrame
0
Bit 3
TxEn
Intel Hex Address: x’19
Motorola Hex Address: x’1A
Bit 2
TxITB
Bit 1
TxFrame
Bit 0
0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Receiver enabled status
0 = Receiver disabled.
1 = Receiver enabled.
Receive ITB
This bit indicates that the last frame received was terminated with an ITB. This
means that the leading character of the next receive frame is included in the BCC cal-
culation.
Receive frame
This bit, when set, indicates that the CD2481 is currently receiving a frame.
Reserved – returns ‘0’ when read.
Transmitter enabled status
0 = Transmitter disabled.
1 = Transmitter enabled.
Transmit ITB
This bit is set if the last frame transmitted ended with and ITB character, that is, the
leading character of the next frame is included in the BCC calculation.
Transmit frame status
This bit, when set, indicates that the CD2481 is currently transmitting a frame.
Reserved – returns ‘0’ when read.
154
Datasheet