LPC1857FET256,551 NXP Semiconductors, LPC1857FET256,551 Datasheet - Page 768

• Manufacturer Part Number: LPC1857FET256,551
• Description: IC MCU 32BIT 1MB FLASH 256LBGA
• Manufacturer: NXP Semiconductors
• Series: LPC18xxr

Specifications of LPC1857FET256,551

• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 150MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, Microwire, SD/MMC, SPI, SSI, SSP, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, DMA, I²S, LCD, Motor Control PWM, POR, PWM, WDT
• Number Of I /o: 80
• Program Memory Size: 1MB (1M x 8)
• Program Memory Type: FLASH
• Eeprom Size: -
• Ram Size: 136K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 16x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 256-LBGA
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

NXP Semiconductors
Table 711. UART1 FIFO Level register (FIFOLVL - address 0x4008 2058) bit description
33.6 Architecture
<Document ID>
User manual
Bit
3:0
7:4
11:8
31:12 -
Symbol
RXFIFILVL
-
TXFIFOLVL
33.5.22 UART1 FIFO Level register
Description
Reflects the current level of the UART1 receiver FIFO.
0 = empty, 0xF = FIFO full.
Reserved. The value read from a reserved bit is not defined.
Reflects the current level of the UART1 transmitter FIFO.
0 = empty, 0xF = FIFO full.
Reserved, the value read from a reserved bit is not defined.
The driver delay time is the delay between the last stop bit leaving the TXFIFO and the
de-assertion of RTS (or DTR). This delay time can be programmed in the 8-bit RS485DLY
register. The delay time is in periods of the baud clock. Any delay time from 0 to 255 bit
times may be programmed.
RS485/EIA-485 output inversion
The polarity of the direction control signal on the RTS (or DTR) pins can be reversed by
programming bit 5 in the U1RS485CTRL register. When this bit is set, the direction control
pin will be driven to logic 1 when the transmitter has data waiting to be sent. The direction
control pin will be driven to logic 0 after the last bit of data has been transmitted.
U1FIFOLVL register is a read-only register that allows software to read the current FIFO
level status. Both the transmit and receive FIFO levels are present in this register.
The architecture of the UART1 is shown below in the block diagram.
The APB interface provides a communications link between the CPU or host and the
UART1.
The UART1 receiver block, U1RX, monitors the serial input line, RXD1, for valid input.
The UART1 RX Shift Register (U1RSR) accepts valid characters via RXD1. After a valid
character is assembled in the U1RSR, it is passed to the UART1 RX Buffer Register FIFO
to await access by the CPU or host via the generic host interface.
The UART1 transmitter block, U1TX, accepts data written by the CPU or host and buffers
the data in the UART1 TX Holding Register FIFO (U1THR). The UART1 TX Shift Register
(U1TSR) reads the data stored in the U1THR and assembles the data to transmit via the
serial output pin, TXD1.
The UART1 Baud Rate Generator block, U1BRG, generates the timing enables used by
the UART1 TX block. The U1BRG clock input source is the APB clock (PCLK). The main
clock is divided down per the divisor specified in the U1DLL and U1DLM registers. This
divided down clock is a 16x oversample clock, NBAUDOUT.
The modem interface contains registers U1MCR and U1MSR. This interface is
responsible for handshaking between a modem peripheral and the UART1.
The interrupt interface contains registers U1IER and U1IIR. The interrupt interface
receives several one clock wide enables from the U1TX and U1RX blocks.
All information provided in this document is subject to legal disclaimers.
Rev. 00.13 — 20 July 2011
Chapter 33: LPC18xx UART1
UM10430
© NXP B.V. 2011. All rights reserved.
Reset value
0x00
NA
0x00
NA
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