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Programmers Model
ARM DUI 0447J
Copyright © 2009-2014, ARM. All rights reserved.
4-38
ID052914
Non-Confidential
Table 4-35
provides information about the UART interfaces.
The PrimeCell UART varies from the industry-standard 16C550 UART device as follows:
•
UART0 has full handshaking signals, RTS, CTS, DSR, DTR, DCD, and RI, but DSR and
CTS are used for remote operation. See the
ARM
®
Versatile
™
Express Configuration
Technical Reference Manual
.
•
Handshaking signals for UART1-3 consist of RTS and CTS.
•
Receive FIFO trigger levels are 1/8, 1/4, 1/2, 3/4, and 7/8.
•
The internal register map address space, and the bit function of each register differ.
•
Information relating to the modem status signals are not available.
•
1.5 stop bits not available, 1 or 2 stop bits only are supported.
•
No independent receive clock.
Table 4-35 UART implementation
Property
Value
Location
Motherboard IO FPGA
Memory base address
•
ARM Legacy memory map:
UART 0
SMB CS7 base a
0x9000
UART 1
SMB CS7 base a
0xA000
UART 2
SMB CS7 base a
0xB000
UART 3
SMB CS7 base a
0xC000
.
•
Cortex-A Series
memory map:
UART 0
SMB CS3 base a
0x90000
UART 1
SMB CS3 base a
0xA0000
UART 2
SMB CS3 base a
0xB0000
UART 3
SMB CS3 base a
0xC0000
UART 4
SMB CS3 base a
0x1B0000
.
Interrupt
•
UART 0: 5
•
UART 1: 6
•
UART 2: 7
•
UART 3: 8.
DMA mapping
See
Table 4-14 on page 4-18
.
Note
You must set
DMAPSR
=
b01
in the SYS_DMAPSR register to select this peripheral for
DMA access.
Release version
ARM UART PL011 r1p3.
Platform Library support
_platform_uart_entry
Handles all channel operations for the UART channels, reading characters, writing
characters, and opening the channel.
Reference documentation
PrimeCell UART (PL011) Technical Reference Manual
.