17-18
Intel® PXA255 Processor
Developer’s Manual
Hardware UART
This is a read-only register. Ignore reads from reserved bits.
17.5.10
Line Control Register (LCR)
The LCR., shown in
Table 17-14
specifies the format for the asynchronous data communications
exchange. The serial data format consists of a start bit, five to eight data bits, an optional parity bit,
and one, one and a half, or two stop bits. The LCR has bits that allow access to the divisor latch and
bits that can cause a break condition.
This is a read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.
Table 17-13. ACR
Bit Definitions
Physical Address
0x4160_002C
Autobaud Count Register (ACR)
PXA255 Processor Hardware UART
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
reserved
Count Value
Reset ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bits
Name
Description
31:16
—
reserved
15:0
ACR
Number of 14.7456 MHz clock cycles within a
start
bit pulse.
Table 17-14. LCR Bit Definitions (Sheet 1 of 2)
Physical Address
0x4160_000C
Line Control Register (LCR)
PXA255 Processor Hardware UART
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
reserved
DL
A
B
SB
STKY
P
EPS
PEN
STB
WL
S
Reset ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
0
0
0
0
0
0
0
0
Bits
Name
Description
31:8
—
reserved
7
DLAB
DIVISOR LATCH ACCESS BIT
Must be set to access the divisor latches of the baud rate generator during a READ or
WRITE operation. Must be cleared to access the receiver buffer, the Transmit Holding
register, or the IER.
0 = Access Transmit Holding register (THR), Receive Buffer register (RBR) and IER.
1 = Access Divisor Latch registers (DLL and DLH)
6
SB
SET BREAK
Causes a break condition to be transmitted to the receiving UART. Acts only on the TXD pin
and has no effect on the transmitter logic. In FIFO mode, wait until the transmitter is idle,
LSR[TEMT]=1, to set and clear SB.
0 = No effect on TXD output
1 = Forces TXD output to 0 (space)
5
STKYP
STICKY PARITY
Forces the bit value at the parity bit location to be the opposite of the EPS bit, rather than
the parity value. This stops parity generation. If PEN = 0, STKYP is ignored.
0 = No effect on parity bit
1 = Forces parity bit to be opposite of EPS bit value
Summary of Contents for PXA255
Page 1: ...Intel PXA255 Processor Developer s Manual January 2004 Order Number 278693 002 ...
Page 24: ...xxiv Intel PXA255 Processor Developer s Manual Contents ...
Page 30: ...1 6 Intel PXA255 Processor Developer s Manual Introduction ...
Page 310: ...7 46 Intel PXA255 Processor Developer s Manual LCD Controller ...
Page 330: ...8 20 Intel PXA255 Processor Developer s Manual Synchronous Serial Port Controller ...
Page 358: ...9 28 Intel PXA255 Processor Developer s Manual I2 C Bus Interface Unit ...
Page 488: ...13 36 Intel PXA255 Processor Developer s Manual AC 97 Controller Unit ...
Page 572: ...16 30 Intel PXA255 Processor Developer s Manual Network SSP Serial Port ...
Page 599: ...Intel PXA255 Processor Developer s Manual 17 27 Hardware UART ...
Page 600: ......