HAL_UARTFeatures (changes)
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Hardware Abstraction Layer
HAL entry points from RISC OS
» HAL_UARTFeatures
HAL_UARTFeatures
(HAL entry #68)
int HAL_UARTFeatures(int port)
| Entry | |
|---|---|
| port | Port number to query |
| Exit | |
|---|---|
| Bit 0 | FIFOs available |
| Bit 1 | DMA available |
| Bit 2 | Modem lines available |
| Bit 3 | Hardware RTS/CTS control available |
| Bit 4 | Transmitter empty IRQ is actually “TX FIFO under threshold” IRQ |
Use
This is an internal call for use by the DualSerial module and should not be used by user code. Instead of calling the HAL directly, user code should interact with the Serial* entries that DualSerial creates in DeviceFS.
Requests information about the available features of the indicated port port.
If bit 4 is set then the transmitter empty IRQ may only change state once the required FIFO level is crossed, and on startup (when the FIFO is empty) this condition will not have been met yet, so the IRQ may not be firing. Therefore the FIFO will need to be filled above the threshold level, e.g. by using HAL_UARTLineStatus bit 8 to work out when to stop filling the FIFO.
See also
Information source: HAL.Tungsten.s.UART in CVS
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