CD2231

Manufacturer Part NumberCD2231
DescriptionCD2231 Intelligent Two-channel Lan And Wan Communications Controller
ManufacturerIntel Corporation
CD2231 datasheet
 


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CD2231 — Intelligent Two-Channel LAN and WAN Communications Controller
RISRl — Asynchronous Mode
Register Name: RISRl
Register Description: Receive Interrupt Status — Low
Default Value: x’00
Access: Byte Read only
Bit 7
Bit 6
Bit 5
Timeout
SCdet2
SCdet1
If RxData in IER is set, these interrupts are enabled.
Bit 7
Timeout – indicates that the receive FIFO is empty, and no data has been received
within the receive timeout period. There is no data character associated with this sta-
tus, and no other status bits are valid if the Time-Out bit is set.
Bits 6:4
Special character detect
SCdet[2:0]
Bit 3
Overrun error – indicates that new data has arrived, but the CD2231 FIFO or holding
registers are full. The new data is lost and the overrun indication is flagged on the
last character received before the overrun occurred.
Bit 2
Parity error – indicates that a parity error has occurred.
Bit 1
Framing error – indicates that a bad Stop bit is detected.
Bit 0
Break – indicates that a break is detected.
RISRl — Async-HDLC / PPP / MNP 4 Mode
Register Name: RISRl
Register Description: Receive Interrupt Status — Low
Default Value: x’00
Access: Byte Read only
Bit 7
Bit 6
Bit 5
0
EOF
RxAbt
If RxData in IER is set, these interrupts are enabled.
Bit 7
Reserved – always returns ‘0’ when read.
128
Bit 4
Bit 3
SCdet0
OE
Status
000
None detected
001
Special Character 1 matched
010
Special Character 2 matched
011
Special Character 3 matched (only if ESCDE is enabled in COR3)
100
Special Character 4 matched (only if ESCDE is enabled in COR3)
Character is within the inclusive range of the characters in the Special
Character Range low and high registers (only if RngDE is enabled in
111
COR3). Special character match can be enabled for error characters by
COR7.
Bit 4
Bit 3
CRC
OE
Intel Hex Address: x’8A
Motorola Hex Address: x’89
Bit 2
Bit 1
Bit 0
PE
FE
Break
Intel Hex Address: x’8A
Motorola Hex Address: x’89
Bit 2
Bit 1
Bit 0
FE
0
Break
Datasheet