Intel PXA255 User Manual

Page 373

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Intel® PXA255 Processor Developer’s Manual

10-17

UARTs

2

PE

Parity Error: Indicates that the received data character does not have the correct even or
odd parity, as selected by the even parity select bit. PE is set upon detection of a parity
error and is cleared when the processor reads the LSR. In FIFO mode, PE shows a parity
error for the character at the front of the FIFO, not the most recently received character.

0 – No Parity error
1 – Parity error has occurred

1

OE

Overrun Error: In non-FIFO mode, indicates that data in the Receive Buffer Register was
not read by the processor before the next character was received. The new character is
lost. In FIFO mode, OE indicates that all 64 bytes of the FIFO are full and the most recently
received byte has been discarded. The OE indicator is set upon detection of an overrun
condition and cleared when the processor reads the LSR.

0 – No data has been lost
1 – Received data has been lost

0

DR

Data Ready: Set when a complete incoming character has been received and transferred
into the Receive Buffer Register or the FIFO. In non-FIFO mode, DR is cleared when the
receive buffer is read. In FIFO mode, DR is cleared if the FIFO is empty (last character has
been read from RBR) or the FIFO is reset with FCR[RESETRF].

0 – No data has been received
1 – Data is available in RBR or the FIFO

Table 10-13. LSR Bit Definitions (Sheet 3 of 3)

Base+0x14

Line Status Register

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

FIF

O

E

TEM

T

TD

R

Q

BI

FE

PE

OE

DR

Reset

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

0

0

0

0

0

Bits

Name

Description

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