Tenstorrent virtual UART APIs

Data Structures
struct	tt_vuart
	In-memory ring buffer descriptor for Tenstorrent virtual UART. More...

Enumerations
enum	tt_vuart_role {   TT_VUART_ROLE_DEVICE ,   TT_VUART_ROLE_HOST }
	Role of the virtual UART in the context of the shared memory buffer. More...

Functions
static size_t	tt_vuart_inst (volatile const struct tt_vuart *vuart)
	Determine the instance number of a virtual UART buffer descriptor.
static uint32_t	tt_vuart_buf_size (uint32_t head, uint32_t tail)
	Determine the size of the given buffer.
static uint32_t	tt_vuart_buf_space (uint32_t head, uint32_t tail, uint32_t cap)
	Determine the free space available in the given buffer.
static bool	tt_vuart_buf_empty (uint32_t head, uint32_t tail)
	Determine if the given buffer is empty.
static bool	tt_vuart_buf_full (uint32_t head, uint32_t tail, uint32_t cap)
	Determine if the given buffer is full.
static int	tt_vuart_poll_in (volatile struct tt_vuart *vuart, unsigned char *p_char, enum tt_vuart_role role)
	Poll the virtual UART buffer for incoming data.
static void	tt_vuart_poll_out (volatile struct tt_vuart *vuart, unsigned char out_char, enum tt_vuart_role role)
	Poll the virtual UART buffer with outgoing data.

Detailed Description

Enumeration Type Documentation

tt_vuart_role

enum tt_vuart_role

Role of the virtual UART in the context of the shared memory buffer.

The virtual UART is a shared memory buffer that is used to communicate between a device and a host. The device and host have different perspectives on the buffer, so the role of the virtual UART is used to clarify the direction of communication.

From the perspective of the device, the transmit buffer is used to send data to the host, and the receive buffer is used to receive data from the host. Conversely, from the perspective of the host, the transmit buffer is used to send data to the device, and the receive buffer is used to receive data from the device.

Enumerator
TT_VUART_ROLE_DEVICE	Device perspective of tt_vuart
TT_VUART_ROLE_HOST	Host perspective of tt_vuart

Function Documentation

tt_vuart_buf_empty()

bool tt_vuart_buf_empty ( uint32_t head, uint32_t tail )

inlinestatic

Determine if the given buffer is empty.

Parameters

head	Head index of the buffer
tail	Tail index of the buffer

Returns

true if the buffer is empty, false otherwise

tt_vuart_buf_full()

bool tt_vuart_buf_full ( uint32_t head, uint32_t tail, uint32_t cap )

inlinestatic

Determine if the given buffer is full.

Parameters

head	Head index of the buffer
tail	Tail index of the buffer
cap	Capacity of the buffer

Returns

true if the buffer is full, false otherwise

tt_vuart_buf_size()

uint32_t tt_vuart_buf_size ( uint32_t head, uint32_t tail )

inlinestatic

Determine the size of the given buffer.

Parameters

head	Head index of the buffer
tail	Tail index of the buffer

Returns

Size of the buffer

tt_vuart_buf_space()

uint32_t tt_vuart_buf_space ( uint32_t head, uint32_t tail, uint32_t cap )

inlinestatic

Determine the free space available in the given buffer.

Parameters

head	Head index of the buffer
tail	Tail index of the buffer
cap	Capacity of the buffer

Returns

Free space available in the buffer

tt_vuart_inst()

size_t tt_vuart_inst ( volatile const struct tt_vuart * vuart )

inlinestatic

Determine the instance number of a virtual UART buffer descriptor.

Parameters

vuart

Pointer to the virtual UART buffer descriptor

Returns

The instance number

tt_vuart_poll_in()

int tt_vuart_poll_in ( volatile struct tt_vuart * vuart, unsigned char * p_char, enum tt_vuart_role role )

inlinestatic

Poll the virtual UART buffer for incoming data.

This method returns one byte of data from the virtual UART buffer, if available. If the buffer is empty, this method returns -1 (EOF).

Parameters

vuart	Pointer to the virtual UART buffer descriptor
p_char	Pointer to the location to store the incoming byte
role	Role with respect to the virtual UART buffer

Returns

The incoming byte, or -1 (EOF) if the buffer is empty

tt_vuart_poll_out()

void tt_vuart_poll_out ( volatile struct tt_vuart * vuart, unsigned char out_char, enum tt_vuart_role role )

inlinestatic

Poll the virtual UART buffer with outgoing data.

This method transmits one byte of data from the virtual UART buffer, if possible. If the buffer is empty, this method simply returns.

If writing to the virtual UART results in buffer overflow, the overflow counter is incremented and the data is discarded.

Parameters

vuart	Pointer to the virtual UART buffer descriptor
out_char	The byte to transmit
role	Role with respect to the virtual UART buffer