usr

         UART Status register.

Module Instance	Base Address	Register Address
`i_uart_0_uart`	`0xFFC02000`	`0xFFC0207C`
`i_uart_1_uart`	`0xFFC02100`	`0xFFC0217C`

Offset: 0x7C

Access: RO

Important: The value of a reserved bit must be maintained in software. When you modify registers containing reserved bit fields, you must use a read-modify-write operation to preserve state and prevent indeterminate system behavior.

Bit Fields
31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16
`rsvd_usr_31to5` `RO 0x0`
15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
`rsvd_usr_31to5` `RO 0x0`											`rff` `RO 0x0`	`rfne` `RO 0x0`	`tfe` `RO 0x1`	`tfnf` `RO 0x1`	`rsvd_busy` `RO 0x0`

usr Fields

Bit

Name

Description

Access

Reset

31:5

rsvd_usr_31to5

Reserved bits [31:5] - Read Only

RO

0x0

rff

Receive FIFO Full.
This bit is only valid when FIFO_STAT == YES. This is used to indicate that the
receive FIFO is completely full. That is:
0 = Receive FIFO not full
1 = Receive FIFO Full
This bit is cleared when the RX FIFO is no longer full.

Value	Description
0	NOTFULL
1	FULL

RO

0x0

rfne

Receive FIFO Not Empty.
This bit is only valid when FIFO_STAT == YES. This is used to indicate that the
receive FIFO contains one or more entries.
0 = Receive FIFO is empty
1 = Receive FIFO is not empty
This bit is cleared when the RX FIFO is empty.

Value	Description
0	EMPTY
1	NOTEMPTY

RO

0x0

tfe

Transmit FIFO Empty.
This bit is only valid when FIFO_STAT == YES. This is used to indicate that the
transmit FIFO is completely empty.
0 = Transmit FIFO is not empty
1 = Transmit FIFO is empty
This bit is cleared when the TX FIFO is no longer empty.

Value	Description
0	NOTEMPTY
1	EMPTY

RO

0x1

tfnf

Transmit FIFO Not Full.
This bit is only valid when FIFO_STAT == YES. This is used to indicate that the
transmit FIFO in not full.
0 = Transmit FIFO is full
1 = Transmit FIFO is not full
This bit is cleared when the TX FIFO is full.

Value	Description
0	FULL
1	NOTFULL

RO

0x1

rsvd_busy

UART Busy.
This bit is only valid when UART_16550_COMPATIBLE == NO. This indicates that a serial
transfer is in progress, when cleared indicates that the DW_apb_uart is idle or inactive.
0 = DW_apb_uart is idle or inactive
1 - DW_apb_uart is busy (actively transferring data)
Note that it is possible for the UART Busy bit to be cleared even though a new
character may have been sent from another device. That is, if the DW_apb_uart
has no data in the THR and RBR and there is no transmission in progress and a start
bit of a new character has just reached the DW_apb_uart. This is due to the fact
that a valid start is not seen until the middle of the bit period and this duration
is dependent on the baud divisor that has been programmed. If a second system clock
has been implemented (CLOCK_MODE == Enabled) the assertion of this bit will also be
delayed by several cycles of the slower clock.

RO

0x0