RBR
Receive Buffer Register, reading this register when the DLAB bit is zero;
Transmit Holding Register, writing to this register when the DLAB is zero;
Divisor Latch (Low), when DLAB bit is one
Module Instance | Base Address | Register Address |
---|---|---|
i_uart_0_uart_address_block | 0xFFC02000 | 0xFFC02000 |
i_uart_1_uart_address_block | 0xFFC02100 | 0xFFC02100 |
Size: 32
Offset: 0x0
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_RBR_31to8 RO 0x0 |
|||||||||||||||
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
RSVD_RBR_31to8 RO 0x0 |
rbr RO 0x0 |
RBR Fields
Bit | Name | Description | Access | Reset |
---|---|---|---|---|
31:8 | RSVD_RBR_31to8 |
Reserved bits [31:8] - Read Only |
RO | 0x0 |
7:0 | rbr |
Receive Buffer Register: This register contains the data byte received on the serial input port (sin) in UART mode or the serial infrared input (sir_in) in infrared mode. The data in this register is valid only if the Data Ready (DR) bit in the Line status Register (LSR) is set. If in non-FIFO mode (FIFO_MODE == NONE) or FIFOs are disabled (FCR[0] set to zero), the data in the RBR must be read before the next data arrives, otherwise it will be overwritten, resulting in an overrun error. If in FIFO mode (FIFO_MODE != NONE) and FIFOs are enabled (FCR[0] set to one), this register accesses the head of the receive FIFO. If the receive FIFO is full and this register is not read before the next data character arrives, then the data already in the FIFO will be preserved but any incoming data will be lost. An overrun error will also occur. |
RO | 0x0 |