Datasheet

UART
Intel
®
Quark™ microcontroller D2000
Datasheet January 2016
194 Document Number: 333577-002EN
Signal Name Direction/
Type
Description
UART_B_DE Logic
Output
UART B Driver Enable (RS485 mode). Used to
control the differential driver of RS485 in
platform/board. This is multiplexed onto
UART_B_RTS pin depending on RS485 or RS232
mode of operation.
UART_B_RE Logic
Output
UART A Receiver Enable (RS485 mode). Used to
control the differential receiver of RS485 in
platform/board. This is multiplexed onto
UART_B_CTS pin depending on RS485 or RS232
mode of operation.
14.2 Features
Both UART instances are configured identically, the following is a list of the UART
controller features:
• Operation compliant with the 16550 Standard
o Start bit
o 5 to 9 bits of Data
o Optional Parity bit (Odd or Even)
o 1, 1.5 or 2 Stop bits
• Baud Rate configurability between 300 baud and 2M baud.
o Maximum baud rate is limited by system clock frequency divided by
16.
o Supported baud rates:
300, 1200, 2400, 4800, 9600, 14400, 19200,
38400, 57600, 76800, 115200; multiples of 38.4kbps and multiples of
115.2kbps upto 2M baud
• Auto Flow Control mode as specified in the 16750 Standard
• Hardware Flow Control
• Software Flow Control (when Hardware Flow Control is disabled)
• Hardware Handshake Interface to support DMA capability
• Interrupt Control
• FIFO support with 16B TX and RX FIFO’s
• Support of RS485
o Differential driver/receiver is external to SoC.
o Driver enable (DE) and Receiver enable (RE) outputs are driven from
SoC to control the differential driver/receiver.
• Fractional clock divider that ensures less than 2% frequency error for most
supported baud rates.
o Fraction resolution is 4-bits.
o Exception: 2.07% error for 1.391 Mbaud, 2.12% for 1.882 Mbaud and
2Mbaud, 2.53% error for 1.684 Mbaud.
• 9-bit data transfer mode to support multi-drop system where one master is
connected to multiple slaves in a system