Device
spim_cs0
spim_somi
spim_simo
spim_clk
SIMO
SIMO
SIMO
SIMO
SCLK
SCLK
SCLK
SCLK
SOMI
SOMI
SOMI
SOMI
CS
CS
CS
CS
Generic
SPI master
device
Generic
SPI slave
device
Generic
SPI slave
device
Generic
SPI slave
device
108-017
McSPI
module m
Functional Description
Figure 24-23. Example of SPI Slave with One Master and Multiple Slave Devices on Channel 0
24.3.3.2 Interrupt Events in Slave Mode
The interrupt events related to the transmitter register state are TX_empty and TX_underflow. The
interrupt events related to the receiver register state are RX_full and RX_overflow.
24.3.3.2.1 TX_EMPTY
The event TX_empty is activated when the channel is enabled and its transmitter register becomes empty.
Enabling channel automatically raises this event. When FIFO buffer is enabled
(MCSPI_CH(I)CONF[FFEW] set to 1), the TX_empty is asserted as soon as there is enough space in
buffer to write a number of byte defined by MCSPI_XFERLEVEL[AEL].
Transmitter register must be load to remove source of interrupt and TX_empty interrupt status bit must be
cleared for interrupt line de-assertion (if event enable as interrupt source).
When FIFO is enabled, no new TX_empty event will be asserted unless the host performs the number of
writes to the transmitter register defined by MCSPI_XFERLEVEL[AEL]. It is the responsibility of the Local
Host to perform the right number of writes.
4023
SPRUH73H – October 2011 – Revised April 2013
Multichannel Serial Port Interface (McSPI)
Copyright © 2011–2013, Texas Instruments Incorporated