OPB16450UART Xilinx Corp., OPB16450UART Datasheet - Page 7

• Manufacturer Part Number: OPB16450UART
• Description: Ds433 August 18, 2004 Product Specification
• Manufacturer: Xilinx Corp.

UART Register Logic
This section tabulates the internal UART registers, including their reset values (if any).
Please
(http://www.national.com/pf/PC/PC16550D.html) for a more detailed description of the register behavior.
Receiver Buffer Register
As shown in
Transmitter Buffer Register
As shown in
Interrupt Enable Register
As shown in
DS433 August 18, 2004
Product Specification
Table 5: Receiver Buffer Register Bit Definitions
Table 6: Transmitter Holding Register Bit Definitions
Location
Location
7-0
7-0
Bit
Bit
refer
Table
Table
Table
Table 4: UART Registers
to
Notes:
1.
Receiver Buffer Register (RBR)
Transmitter Holding Register (THR)
Interrupt Enable Register (IER)
Interrupt Identification Register (IIR)
Line Control Register (LCR)
Modem Control Register (MCR)
Line Status Register (LSR)
Modem Status Register (MSR)
Scratch Register (SCR)
Divisor Register (DLL)
Divisor Register (DLM)
Name
Name
5, the Receiver Buffer Register contains the last received character.
6, the Transmitter Holding Register contains the character to be transmitted next.
7, the Interrupt Enable Register contains the bits which enable interrupts.
RBR
THR
X denotes a don’t care
the
National
Register Name
Access
Access
Read
Write
Semiconductor
Reset Value
Reset Value
“00000000"
“11111111”
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1-800-255-7778
PC16550D
X + C_BASEADDR + 0x100C
X + C_BASEADDR + 0x101C
X + C_BASEADDR + 0x1010
X + C_BASEADDR + 0x1014
X + C_BASEADDR + 0x1018
0 + C_BASEADDR + 0x1000
0 + C_BASEADDR + 0x1000
0 + C_BASEADDR + 0x1004
0 + C_BASEADDR + 0x1008
1 + C_BASEADDR + 0x1000
1 + C_BASEADDR + 0x1004
LCR(7)
1
+ C_BASEADDR +
Address
RBR. Last received character
THR. Holds the character to be transmitted next
UART
with
FIFOs
Description
Description
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
data
Access
Read
Write
Read
sheet
OPB 16450 UART
(June,
1995),
7