|Registers / SPI0/1 Register description|
The STAT register provides SPI status flags for software to read, and a control bit for forcing an end of transfer. Flags other than read-only flags may be cleared by writing ones to corresponding bits of STAT.
STAT contains 2 error flags (in slave mode only): RXOV and TXUR. These are receiver overrun and transmit underrun, respectively. If either of these errors occur during operation, the SPI should be disabled, then re-enabled in order to make sure all internal states are cleared before attempting to resume operation.
In this register, the following notation is used: RO = Read-only, W1 = write 1 to clear..
|0||RXRDY||Receiver Ready flag. When 1, indicates that data is available to be read from the receiver buffer. Cleared after a read of the RXDAT register.||0||RO|
|1||TXRDY||Transmitter Ready flag. When 1, this bit indicates that data may be written to the transmit buffer. Previous data may still be in the process of being transmitted. Cleared when data is written to TXDAT or TXDATCTL until the data is moved to the transmit shift register.||1||RO|
|2||RXOV||Receiver Overrun interrupt flag. This flag applies only to slave mode (Master = 0). This flag is set when the beginning of a received character is detected while the receiver buffer is still in use. If this occurs, the receiver buffer contents are preserved, and the incoming data is lost. Data received by the SPI should be considered undefined if RxOv is set.||0||W1|
|3||TXUR||Transmitter Underrun interrupt flag. This flag applies only to slave mode (Master = 0). In this case, the transmitter must begin sending new data on the next input clock if the transmitter is idle. If that data is not available in the transmitter holding register at that point, there is no data to transmit and the TXUR flag is set. Data transmitted by the SPI should be considered undefined if TXUR is set.||0||W1|
|4||SSA||Slave Select Assert. This flag is set whenever any slave select transitions from deasserted to asserted, in both master and slave modes. This allows determining when the SPI transmit/receive functions become busy, and allows waking up the device from reduced power modes when a slave mode access begins. This flag is cleared by software.||0||W1|
|5||SSD||Slave Select Deassert. This flag is set whenever any asserted slave selects transition to deasserted, in both master and slave modes. This allows determining when the SPI transmit/receive functions become idle. This flag is cleared by software.||0||W1|
|6||STALLED||Stalled status flag. This indicates whether the SPI is currently in a stall condition.||0||RO|
|7||ENDTRANSFER||End Transfer control bit. Software can set this bit to force an end to the current transfer when the transmitter finishes any activity already in progress, as if the EOT flag had been set prior to the last transmission. This capability is included to support cases where it is not known when transmit data is written that it will be the end of a transfer. The bit is cleared when the transmitter becomes Idle as the transfer comes to an end. Forcing an end of transfer in this manner causes any specified FrameDelay and TransferDelay to be inserted.||0||RO/W1|
|8||MSTIDLE||Master idle status flag. This bit is 1 whenever the SPI master function is fully idle. This means that the transmit holding register is empty and the transmitter is not in the process of sending data.||1||RO|
|31:9||-||Reserved. Read value is undefined, only zero should be written.||NA||NA|
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