`define UART_ADDR_WIDTH 3
`define UART_DATA_WIDTH 8

// Register addresses
`define UART_REG_RB		3'd0	// RBR - receiver buffer
`define UART_REG_TR     3'd0	// TBR - transmitter
`define UART_REG_IE		3'd1	// IER - Interrupt enable
`define UART_REG_II     3'd2	// IIR - Interrupt identification
`define UART_REG_FC     3'd2	// FCR - FIFO control
`define UART_REG_LC		3'd3	// LCR - Line Control
`define UART_REG_MC		3'd4	// MCR - Modem control
`define UART_REG_LS     3'd5	// LSR - Line status
`define UART_REG_MS     3'd6	// MSR - Modem status
`define UART_REG_SR     3'd7	// SCR - Scratch register
`define UART_REG_DL1	3'd0	// Divisor latch bytes (1-2)
`define UART_REG_DL2	3'd1

// IER - Interrupt Enable register bits
`define UART_IE_RDA		0		// Received Data available interrupt
`define UART_IE_THRE	1		// Transmitter Holding Register empty interrupt
`define UART_IE_RLS		2		// Receiver Line Status Interrupt
`define UART_IE_MS		3		// Modem Status Interrupt

// IIR - Interrupt Identification register bits
`define UART_II_IP		0		// Interrupt pending when 0
`define UART_II_II		3:1		// Interrupt identification

// IIR - Interrupt identification values for bits 3:1
`define UART_II_RLS		3'b011	// Receiver Line Status
`define UART_II_RDA		3'b010	// Receiver Data available
`define UART_II_TI		3'b110	// Timeout Indication
`define UART_II_THRE	3'b001	// Transmitter Holding Register empty
`define UART_II_MS		3'b000	// Modem Status

// FCR - FIFO Control Register bits
`define UART_FC_TL		1:0		// Trigger level

// FCR - FIFO trigger level values
`define UART_FC_1		2'b00
`define UART_FC_8		2'b01
`define UART_FC_16		2'b10
`define UART_FC_28		2'b11

// LCR - Line Control register bits
`define UART_LC_BITS	1:0		// bits in character
`define UART_LC_SB		2		// stop bits
`define UART_LC_PE		3		// parity enable
`define UART_LC_EP		4		// even parity
`define UART_LC_SP		5		// stick parity
`define UART_LC_BC		6		// Break control
`define UART_LC_DL		7		// Divisor Latch access bit

// MCR - Modem Control register bits
`define UART_MC_DTR		0
`define UART_MC_RTS		1
`define UART_MC_OUT1	2
`define UART_MC_OUT2	3
`define UART_MC_LB		4		// Loopback mode
`define UART_MC_AFC		5		// !!NEW -- auto flow control enable

// LSR - Line Status Register bits
`define UART_LS_DR		0		// Data ready
`define UART_LS_OE		1		// Overrun Error
`define UART_LS_PE		2		// Parity Error
`define UART_LS_FE		3		// Framing Error
`define UART_LS_BI		4		// Break interrupt
`define UART_LS_TFE		5		// Transmit FIFO is empty
`define UART_LS_TE		6		// Transmitter Empty indicator
`define UART_LS_EI		7		// Error indicator

`define UART_LS_ERR		4:1

// MSR - Modem Status Register bits
`define UART_MS_DCTS	0		// Delta signals
`define UART_MS_DDSR	1
`define UART_MS_TERI	2
`define UART_MS_DDCD	3
`define UART_MS_CCTS	4		// Complement signals
`define UART_MS_CDSR	5
`define UART_MS_CRI		6
`define UART_MS_CDCD	7

`define MSR_CSIGS		7:4
`define MSR_DSIGS		3:0

// FIFO parameter defines

`define UART_FIFO_WIDTH		8
`define UART_FIFO_DEPTH		16
`define UART_FIFO_POINTER_W	4
`define UART_FIFO_COUNTER_W	5
// receiver fifo has width 11 because it has break, parity and framing error bits
`define UART_FIFO_REC_WIDTH	11

`define UART_RF_FE		8
`define UART_RF_PE		9
`define UART_RF_BI		10