CD2481 Datasheet, PDF (156/222 Pages) Intel Corporation – Programmable Four-Channel Communications Controller

CD2481 — Programmable Four-Channel Communications Controller
CSR -–X.21 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
0
RxSpc
0
Bit 3
TxEn
Intel Hex Address: x’19
Motorola Hex Address: x’1A
Bit 2
0
Bit 1
TxSpc
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.
Reserved – returns ‘0’ when read.
Receive special
This bit, when set, indicates that the CD2481 is currently in a steady state condition.
Such conditions generate a receive special character interrupt.
Reserved – returns ‘0’ when read.
Transmitter enabled status
0 = Transmitter disabled.
1 = Transmitter enabled.
Reserved – returns ‘0’ when read.
Transmit special
This bit, when set, indicates that the CD2481 is currently transmitting an ETC com-
mand, as defined in COR2.
Reserved – returns ‘0’ when read.
CSR –Async-HDLC/PPP 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
RxFloff
RxFrame
Ridle
Bit 3
TxEn
Bit 7
RxEn – Receiver enabled status
When set, the receiver is enabled.
When clear, the receiver is disabled.
Intel Hex Address: x’19
Motorola Hex Address: x’1A
Bit 2
TxFloff
Bit 1
TxFrame
Bit 0
Tidle
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Datasheet