CD2231

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


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Intelligent Two-Channel LAN and WAN Communications Controller — CD2231
8.6.4.10
Receive Current Buffer Address Register — Upper (RCBADRU)
Register Name: RCBADRU
Register Description: Current Receive Buffer Address, upper word
Default Value: x’0000
Access: Word Read Only
Bit 15
Bit 14
Bit 13
Bit 7
Bit 6
Bit 5
These registers contain the address of the current DMA buffer being used for receive data, updated
at the end of receive data transfers. These registers are for the private use of the CD2231 to manage
DMA transfers. In Asynchronous mode, the host can read this register during a receive exception
interrupt to determine how much data is in the buffer. The address is the location of the next
character to be transferred to the buffer. The host needs this information to process newly arrived
data in the buffer if used in Append mode, and a data timeout has occurred. The address is also
needed if an exception has occurred, and a gap is to be left in the DMA (see the description of the
Gap bits in
Section 8.5.2.7 on page
bus error during receive data transfer, this register provides the start address of the transfer causing
the bus error.
8.6.5
DMA Transmit Registers
8.6.5.1
A Transmit Buffer Address Register — Lower (ATBADRL)
Register Name: ATBADRL
Register Description: Transmit Buffer ‘A’ 32-bit Address, lower word
Default Value: x’0000
Access: Word Read/Write
Bit 15
Bit 14
Bit 13
Bit 7
Bit 6
Bit 5
Datasheet
Bit 12
Bit 11
Binary address value, 32-bit address, bits 31:24
Bit 4
Bit 3
Binary address value, 32-bit address, bits 23:16
131) for the insertion of status information by the host. For a
Bit 12
Bit 11
Binary address value, 32-bit address, bits 15:8
Bit 4
Bit 3
Binary address value, 32-bit address, bits 7:0
Intel Hex Address: x’3E
Motorola Hex Address: x’3C
Bit 10
Bit 9
Bit 8
Bit 2
Bit 1
Bit 0
Intel Hex Address: x’50
Motorola Hex Address: x’52
Bit 10
Bit 9
Bit 8
Bit 2
Bit 1
Bit 0
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