RTEMS
5.0.0
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Typedefs | |
typedef enum ALT_16550_DATABITS_e | ALT_16550_DATABITS_t |
typedef enum ALT_16550_STOPBITS_e | ALT_16550_STOPBITS_t |
typedef enum ALT_16550_PARITY_e | ALT_16550_PARITY_t |
typedef enum ALT_16550_LINE_STATUS_e | ALT_16550_LINE_STATUS_t |
Enumerations | |
enum | ALT_16550_DATABITS_e { ALT_16550_DATABITS_5 = 0, ALT_16550_DATABITS_6 = 1, ALT_16550_DATABITS_7 = 2, ALT_16550_DATABITS_8 = 3 } |
enum | ALT_16550_STOPBITS_e { ALT_16550_STOPBITS_1 = 0, ALT_16550_STOPBITS_2 = 1 } |
enum | ALT_16550_PARITY_e { ALT_16550_PARITY_DISABLE = 0, ALT_16550_PARITY_ODD = 1, ALT_16550_PARITY_EVEN = 2 } |
enum | ALT_16550_LINE_STATUS_e { ALT_16550_LINE_STATUS_RFE = 1 << 7, ALT_16550_LINE_STATUS_TEMT = 1 << 6, ALT_16550_LINE_STATUS_THRE = 1 << 5, ALT_16550_LINE_STATUS_BI = 1 << 4, ALT_16550_LINE_STATUS_FE = 1 << 3, ALT_16550_LINE_STATUS_PE = 1 << 2, ALT_16550_LINE_STATUS_OE = 1 << 1, ALT_16550_LINE_STATUS_DR = 1 << 0 } |
Functions | |
ALT_STATUS_CODE | alt_16550_line_config_set (ALT_16550_HANDLE_t *handle, ALT_16550_DATABITS_t databits, ALT_16550_PARITY_t parity, ALT_16550_STOPBITS_t stopbits) |
ALT_STATUS_CODE | alt_16550_line_break_enable (ALT_16550_HANDLE_t *handle) |
ALT_STATUS_CODE | alt_16550_line_break_disable (ALT_16550_HANDLE_t *handle) |
ALT_STATUS_CODE | alt_16550_line_status_get (ALT_16550_HANDLE_t *handle, uint32_t *status) |
This group of APIs provides access, configuration, and control of the UART Line interface.
typedef enum ALT_16550_DATABITS_e ALT_16550_DATABITS_t |
This type definition enumerates the supported databits per frame.
typedef enum ALT_16550_LINE_STATUS_e ALT_16550_LINE_STATUS_t |
This type definition enumerates the set of UART line status conditions as register mask values.
typedef enum ALT_16550_PARITY_e ALT_16550_PARITY_t |
This type definition enumerates the possible parity to use per frame.
typedef enum ALT_16550_STOPBITS_e ALT_16550_STOPBITS_t |
This type definition enumerates the supported stopbits per frame.
enum ALT_16550_DATABITS_e |
This type definition enumerates the supported databits per frame.
This type definition enumerates the set of UART line status conditions as register mask values.
Enumerator | |
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ALT_16550_LINE_STATUS_RFE | Receiver FIFO Error. This status indicates that one or more parity error, framing error, or break indication exists in the receiver FIFO. It is only set when FIFO is enabled. This status cleared when line status is read, the character with the issue is at the top of the FIFO, and when no other issues exist in the FIFO. |
ALT_16550_LINE_STATUS_TEMT | Transmitter EMpTy (Empty). This status indicates that transmitter shift register is empty. If FIFOs are enabled, the status is set when the transmitter FIFO is also empty. This status is cleared when the transmitter shift registers is loaded by writing to the UART transmitter buffer or transmitter FIFO if FIFOs are enabled. This is done by calling alt_16550_write() and alt_16550_fifo_write() respectively. |
ALT_16550_LINE_STATUS_THRE | Transmitter Holding Register Empty. This status indicates that the transmitter will run out of data soon. The definition of soon depends on whether the FIFOs are enabled. If FIFOs are disabled, this status indicates that the transmitter will run out of data to send after the current transmit shift register completes. In this case, this status is cleared when the data is written to the UART. This can be done by calling alt_16550_write(). If FIFOs are enabled, this status indicates that the transmitter FIFO level is below the transmitter trigger level specified. In this case, this status is cleared by writing a sufficiently large buffer to the transmitter FIFO such that the FIFO is filled above the transmitter trigger level specified by calling alt_16550_fifo_write() or by adjusting the transmitter trigger level appropriately by calling alt_16550_fifo_trigger_set_tx(). |
ALT_16550_LINE_STATUS_BI | Break Interrupt. This status indicates that a break interrupt sequence is detected in the incoming serial data. This happens when the the data is 0 for longer than a frame would normally be transmitted. The break interrupt status is cleared by reading the line status by calling alt_16550_line_status_get(). If FIFOs are enabled, this status will be set when the character with the break interrupt status is at the top of the receiver FIFO. |
ALT_16550_LINE_STATUS_FE | Framing Error. This status indicates that a framing error occurred in the receiver. This happens when the receiver detects a missing or incorrect number of stopbit(s). If FIFOs are enabled, this status will be set when the character with the framing error is at the top of the FIFO. When a framing error occurs, the UART attempts to resynchronize with the transmitting UART. This status is also set if break interrupt occurred. |
ALT_16550_LINE_STATUS_PE | Parity Error. This status indicates that a parity error occurred in the receiver. If FIFOs are enabled, this status will be set when the character with the parity error is at the top of the receiver FIFO. This status is also set if a break interrupt occurred. |
ALT_16550_LINE_STATUS_OE | Overrun Error. This status indicates that an overrun occurred in the receiver. If FIFOs are disabled, the arriving character will overwrite the existing character in the receiver. Any previously existing character(s) will be lost. If FIFOs are disabled, the arriving character will be discarded. The buffer will continue to contain the preexisting characters. |
ALT_16550_LINE_STATUS_DR | Data Ready. This status indicates that the receiver or receiver FIFO contains at least one character. |
enum ALT_16550_PARITY_e |
This type definition enumerates the possible parity to use per frame.
enum ALT_16550_STOPBITS_e |
ALT_STATUS_CODE alt_16550_line_break_disable | ( | ALT_16550_HANDLE_t * | handle | ) |
Stops transmitting a break condition.
handle | The UART device handle. |
ALT_E_SUCCESS | The operation was successful. |
ALT_E_ERROR | The operation failed. |
ALT_E_BAD_ARG | The given UART device handle is invalid. |
ALT_STATUS_CODE alt_16550_line_break_enable | ( | ALT_16550_HANDLE_t * | handle | ) |
Starts transmitting a break condition by transmitting a logic 0 state longer than a frame would normally be transmitted.
handle | The UART device handle. |
ALT_E_SUCCESS | The operation was successful. |
ALT_E_ERROR | The operation failed. |
ALT_E_BAD_ARG | The given UART device handle is invalid. |
ALT_STATUS_CODE alt_16550_line_config_set | ( | ALT_16550_HANDLE_t * | handle, |
ALT_16550_DATABITS_t | databits, | ||
ALT_16550_PARITY_t | parity, | ||
ALT_16550_STOPBITS_t | stopbits | ||
) |
Sets the configuration for a given character frame.
handle | The UART device handle. |
databits | The number of databits for each character frame. |
parity | The parity to use for each character frame. |
stopbits | The number of stopbits for each character frame. |
ALT_E_SUCCESS | The operation was successful. |
ALT_E_ERROR | The operation failed. |
ALT_E_BAD_ARG | The given UART device handle is invalid. |
ALT_STATUS_CODE alt_16550_line_status_get | ( | ALT_16550_HANDLE_t * | handle, |
uint32_t * | status | ||
) |
Reads the line status from the UART.
handle | The UART device handle. |
status | [out] Pointer to an output parameter that contains the current line status of the UART. |
ALT_E_SUCCESS | The operation was successful. |
ALT_E_ERROR | The operation failed. |
ALT_E_BAD_ARG | The given UART device handle is invalid. |