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Section 17–4.14, Nxp semiconductors – NXP Semiconductors LPC24XX UM10237 User Manual

Page 458

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UM10237_4

© NXP B.V. 2009. All rights reserved.

User manual

Rev. 04 — 26 August 2009

458 of 792

NXP Semiconductors

UM10237

Chapter 17: LPC24XX UART1

4.13 UART1 Scratch Pad Register (U1SCR - 0xE001 001C)

The U1SCR has no effect on the UART1 operation. This register can be written and/or
read at user’s discretion. There is no provision in the interrupt interface that would indicate
to the host that a read or write of the U1SCR has occurred.

4.14 UART1 Auto-baud Control Register (U1ACR - 0xE001 0020)

The UART1 Auto-baud Control Register (U1ACR) controls the process of measuring the
incoming clock/data rate for the baud rate generation and can be read and written at
user’s discretion.

5

DSR

Data Set Ready State. Complement of input signal DSR. This bit is
connected to U1MCR[0] in modem loopback mode.

0

6

RI

Ring Indicator State. Complement of input RI. This bit is connected
to U1MCR[2] in modem loopback mode.

0

7

DCD

Data Carrier Detect State. Complement of input DCD. This bit is
connected to U1MCR[3] in modem loopback mode.

0

Table 409. UART1 Modem Status Register (U1MSR - address 0xE001 0018) bit description

Bit Symbol Value Description

Reset
Value

Table 410. UART1 Scratch Pad Register (U1SCR - address 0xE001 0014) bit description

Bit Symbol Description

Reset Value

7:0 Pad

A readable, writable byte.

0x00

Table 411. Auto-baud Control Register (U1ACR - address 0xE001 0020) bit description

Bit

Symbol

Value Description

Reset value

0

Start

This bit is automatically cleared after auto-baud
completion.

0

0

Auto-baud stop (auto-baud is not running).

1

Auto-baud start (auto-baud is running).Auto-baud run
bit. This bit is automatically cleared after auto-baud
completion.

1

Mode

Auto-baud mode select bit.

0

0

Mode 0.

1

Mode 1.

2

AutoRestart 0

No restart

0

1

Restart in case of time-out (counter restarts at next
UART1 Rx falling edge)

0

7:3

-

NA

Reserved, user software should not write ones to
reserved bits. The value read from a reserved bit is not
defined.

0

8

ABEOIntClr

End of auto-baud interrupt clear bit (write only
accessible).

0

0

Writing a 0 has no impact.

1

Writing a 1 will clear the corresponding interrupt in the
U1IIR.