Multichannel Serial Interfaces
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9.5.1.3
Interface Management
Interrupts Generation
Three physical interrupts are available for real-time management of the MCSI
by the DSP:
-
RX_INT (data receive interrupt)
-
TX_INT (data transmit interrupt)
-
FERR_INT (frame duration error interrupt)
RX_INT, TX_INT, and FERR_INT are maskable with dedicated programmable
control bits of the interrupt register INTERRUPTS_REG.
-
RX_INT is masked when MASK_IT_RX = 0.
-
TX_INT is masked when MASK_IT_TX = 0.
-
FERR_INT is masked when MASK_IT_ERROR = 0.
Each interrupt is associated with a flag bit in the STATUS_REG register that
is set to 1 when the interrupt is generated. To acknowledge the interrupt and
release the corresponding physical signal, the DSP must write a 1 at the bit
location in the status register. The following list provides interrupt/flag bit
associations:
-
RX_INT (RX_READY flag and acknowledge bit)
-
TX_INT (TX_READY flag and acknowledge bit)
-
FERR_INT (FRAME _ERROR flag and acknowledge bit)
Receive Interrupt
The receive interrupt is generated every frame after the completion of the
reception of a data word:
-
In single-channel mode, the interrupt is generated one half-clock period
(plus a synchronization delay) after the reception of the word.
-
In multichannel mode, the interrupt is generated one half-clock period
(plus a synchronization delay) after the reception of the word of the
channel whose number is defined by the NB_CHAN_IT_RX parameter of
INTERRUPTS_REG register.
Note:
If MCSI is in slave mode, the clock must be driven after valid data reception
until the interrupt is generated and must not be gated before then, because
the interrupt is generated on the MCSI interface clock.