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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—Universal Asynchronous
Receiver-Transmitter (UART)
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
Developer’s Manual
August 2006
762
Order Number: 306262-004US
The following sample register-summary table indicates, in parentheses, which
paragraph tags are cross-referenced in the individual register tables.
14.5.1
Receive Buffer Register
RS
Read/Set
WO
Write Only
RW
Read/Write
NA
Not Accessible
RW1C
Normal Read
Write ‘1’ to clear
RW1S
Normal Read
Write ‘1’ to set
Table 249.
Register Legend
Attribute
Legend
Attribute
Legend
Table 250.
UART Registers Overview
Address
DLAB
Access
Name
Description
0xC800_X000
0
RO
RBR
Receive Buffer Register
0
WO
THR
Transmit Holding Register
1
RW
DLL
Divisor Latch Low Register
0x C800_X004
0
RW
IER
Interrupt Enable Register
1
RW
DLH
Divisor Latch High Register
0x C800_X008
0/1
RO
IIR
Interrupt Identification Register
0/1
WO
FCR
FIFO Control Register
0x C800_X00C
0/1
RW
LCR
Line Control Register
0x C800_X010
0/1
RW
MCR
Modem Control Register
0x C800_X014
0/1
RO
LSR
Line Status Register
0x C800_X018
0/1
RO
MSR
Modem Status Register
0x C800_X01C
0/1
RW
SPR
Scratch-Pad Register
0x C800_X020
0
RW
ISR
Slow Infrared Select Register
†
The X in the value C800_X000 is used to denote that this could be a value of either 0 or 1 depending
upon if it is UART 0(High Speed UART) or UART 1(Console UART), respectively. This is the same for
all other addresses to the UARTs.
Register Name:
RBR
Hex Offset Address:
0xC800 X000
Reset Hex Value:
0x00000000
Register
Description:
Receive Buffer Register
Access: Read Only.
31
8
7
0
(Reserved)
RBR