Cyclone® V Hard Processor System Technical Reference Manual

ID 683126
Date 8/28/2023
Public
Document Table of Contents

22.2. UART Controller Block Diagram and System Integration

Figure 121. UART Block Diagram


Table 208.  UART Controller Block Descriptions

Block

Description

Slave interface

Slave interface between the component and L4 peripheral bus.

Register block

Provides main UART control, status, and interrupt generation functions.†

FIFO buffer

Provides FIFO buffer control and storage. †

Baud clock generator

Generates the transmitter and receiver baud clock. With a reference clock of 100 MHz, the UART controller supports transfer rates of 95 baud to 6.25 Mbaud. This supports communication with all known 16550 devices. The baud rate is controlled by programming the interrupt enable or divisor latch high (IER_DLH) and receive buffer, transmit holding, or divisor latch low (RBR_THR_DLL) registers.

Serial transmitter

Converts parallel data written to the UART into serial data and adds all additional bits, as specified by the control register, for transmission. This makeup of serial data, referred to as a character, exits the block in serial UART. †

Serial receiver

Converts the serial data character (as specified by the control register) received in the UART format to parallel form. Parity error detection, framing error detection and line break detection is carried out in this block. †

DMA interface

The UART controller includes a DMA controller interface to indicate when received data is available or when the transmit FIFO buffer requires data. The DMA requires two channels, one for transmit and one for receive. The UART controller supports single and burst transfers. You can use DMA in FIFO buffer and non-FIFO buffer mode.