CD2231 Intel Corporation, CD2231 Datasheet - Page 122

• Manufacturer Part Number: CD2231
• Description: CD2231 Intelligent Two-channel Lan And Wan Communications Controller
• Manufacturer: Intel Corporation

CD2231 — Intelligent Two-Channel LAN and WAN Communications Controller
8.5
8.5.1
8.5.1.1
122
Register Name: LIVR
Register Description: Local Interrupt Vector
Default Value: x’00
Access: Byte Read/Write
Bit 7
X
Note: If the transmit clock source is a 1 clock on the TXCIN pin, this signal cannot be driven on
Note: Note that because the CD2231 provides a unique Local Interrupt Vector register for each channel,
TXCOUT/DTR*.
Bit 3
Bit 2
Bit 1
Bit 0
Interrupt Registers
General Interrupt Registers
Local Interrupt Vector Register (LIVR)
The host effectively controls bits 7:2; the device provides bits 1 and 0 within an interrupt
acknowledge context.
The CD2231 has one Local Interrupt Vector register per channel, each with six host-defined bits.
The host can opt to embed the channel number and the protocol in use on the channel in the
channel vector. The CD2231 supplies two modified bits signifying the type of interrupt service
required.
Bits 7:2
Bits 1:0
the host has the option to include the channel number within the interrupt vector.
Bit 6
X
Reserved – must be ‘0’.
Reserved – returns ‘0’ when read; writing has no effect
DTR – Current state of data terminal ready output
RTS – Current state of request to send output
User-defined. These six bits can be used as the CD2231 device ID number.
Interrupt type. These two bits indicate the group/type of interrupt occurring.
Bit 5
X
IT[1:0]
01
10
11
00
Group/Type
Group 2: Transmit data interrupt
Group 3: Receive exception interrupt
Group 1: Modem signal change interrupt/general
timer interrupt
Group 3: Receive data interrupt
Bit 4
X
Bit 3
X
Bit 2
X
Motorola Hex Address: x’09
Bit 1
IT1
Intel Hex Address: x’0A
Datasheet
Bit 0
IT0