AUCOHL_UART

A more complete UART

The Interface

Generic name	Value	Description
MDW	9	Maximum data word width
FAW	4	FIFO Address Width; $FIFO\ Depth=2^{FAW}$
SC	8	Number of Samples
GFLEN	8	Input Glitch Filter Length

Port name	Direction	Type
clk	input	wire
rst_n	input	wire
prescaler	input	wire [15:0]
en	input	wire
tx_en	input	wire
rx_en	input	wire
rd	input	wire
wr	input	wire
wdata	input	wire [MDW-1:0]
data_size	input	wire [3:0]
stop_bits_count	input	wire
parity_type	input	wire [2:0]
txfifotr	input	wire [3:0]
rxfifotr	input	wire [3:0]
match_data	input	wire [MDW-1:0]
timeout_bits	input	wire [5:0]
loopback_en	input	wire
glitch_filter_en	input	wire
tx_empty	output	wire
tx_full	output	wire
tx_level	output	wire [FAW-1:0]
tx_level_below	output	wire
rdata	output	wire [MDW-1:0]
rx_empty	output	wire
rx_full	output	wire
rx_level	output	wire [FAW-1:0]
rx_level_above	output	wire
break_flag	output	wire
match_flag	output	wire
frame_error_flag	output	wire
parity_error_flag	output	wire
overrun_flag	output	wire
timeout_flag	output	wire
rx	input	wire
tx	output	wire

This section covers the I/O register definitions which are the same for the provided bus wrappers.

Name	Offset	Reset Value	Access Mode	Description
RXDATA	0000	0x00000000	r	RX Data register; the interface to the Receive FIFO.
TXDATA	0004	0x00000000	w	TX Data register; ; the interface to the Receive FIFO.
PR	000c	0x00000000	w	The Prescaler register; used to determine the baud rate. $Baud\ Rate = (Clock\ freq.)/((PR+1)\times16)$.
CTRL	0008	0x00000000	w	UART Control Register
CFG	0010	0x00003F08	w	UART Configuration Register
FIFOCTRL	0014	0x00000000	w	FIFO Control Register
FIFOS	0018	0x00000000	r	FIFO Status Register
MATCH	001c	0x00000000	w	Match Register
IM	0f00	0x00000000	w	Interrupt Mask Register; write 1/0 to enable/disable interrupts; check the interrupt flags table for more details
RIS	0f08	0x00000000	w	Raw Interrupt Status; reflects the current interrupts status;check the interrupt flags table for more details
MIS	0f04	0x00000000	w	Masked Interrupt Status; On a read, this register gives the current masked status value of the corresponding interrupt. A write has no effect; check the interrupt flags table for more details
IC	0f0c	0x00000000	w	Interrupt Clear Register; On a write of 1, the corresponding interrupt (both raw interrupt and masked interrupt, if enabled) is cleared; check the interrupt flags table for more details

RX Data register; the interface to the Receive FIFO.

TX Data register; ; the interface to the Receive FIFO.

The Prescaler register; used to determine the baud rate. $baud_rate = clock_freq/((PR+1)*16)$.

UART Control Register

bit	field name	width	description
0	en	1	UART enable
1	txen	1	UART Transmitter enable
2	rxen	1	UART Receiver enable
3	lpen	1	Loopback (connect RX and TX pins together) enable
4	gfen	1	UART Glitch Filer on RX enable

UART Configuration Register

bit	field name	width	description
0	wlen	4	Data word length: 5-9 bits
4	stp2	1	Two Stop Bits Select
5	parity	3	Parity Type: 000: None, 001: odd, 010: even, 100: Sticky 0, 101: Sticky 1
8	timeout	6	Receiver Timeout measured in number of bits

FIFO Control Register

bit	field name	width	description
0	TXLT	4	Transmit FIFO Level Threshold
8	RXLT	4	Receive FIFO Level Threshold

FIFO Status Register

bit	field name	width	description
0	RXL	4	Receive FIFO Level
8	TXL	4	Transmit FIFO Level

Match Register

The following are the bit definitions for the interrupt registers: IM, RIS, MIS, and IC.

Bit	Flag	Width	Description
0	TXE	1	Transmit FIFO is Empty.
1	RXF	1	Receive FIFO is Full.
2	TXB	1	Transmit FIFO level is Below Threshold.
3	RXA	1	Receive FIFO level is Above Threshold.
4	BRK	1	Line Break; 13 consecutive 0's have been detected on the line.
5	MATCH	1	Match; the receive data matches the MATCH register.
6	FE	1	Framing Error; the receiver does not see a "stop" bit at the expected "stop" bit time.
7	PRE	1	Parity Error; the receiver calculated parity does not match the received one.
8	OR	1	Overrun; data has been received but the RX FIFO is full.
9	RTO	1	Receiver Timeout; no data has been received for the time of a specified number of bits.