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- SERIAL COMMUNICATIONS INTERFACE (SCI)
SERIAL COMMUNICATIONS INTERFACE (Cont’d)
INTERRUPT MASK REGISTER (IMR)
R246 - Read/Write
Reset value: 0xx00000
Bit 7 = BSN:
Buffer or shift register empty inter-
rupt.
This bit selects the source of the transmitter regis-
ter empty interrupt.
0: Select a Shift Register Empty as source of a
Transmitter Register Empty interrupt.
1: Select a Buffer Register Empty as source of a
Transmitter Register Empty interrupt.
Bit 6 = RXEOB:
Received End of Block.
This bit is set by hardware only and must be reset
by software. RXEOB is set after a receiver DMA
cycle to mark the end of a data block.
0: Clear the interrupt request.
1: Mark the end of a received block of data.
Bit 5 = TXEOB:
Transmitter End of Block.
This bit is set by hardware only and must be reset
by software. TXEOB is set after a transmitter DMA
cycle to mark the end of a data block.
0: Clear the interrupt request.
1: Mark the end of a transmitted block of data.
Bit 4 = RXE:
Receiver Error Mask.
0: Disable Receiver error interrupts (OE, PE, and
FE pending bits in the S_ISR register).
1: Enable Receiver error interrupts.
Bit 3 = RXA:
Receiver Address Mask.
0: Disable Receiver Address interrupt (RXAP
pending bit in the S_ISR register).
1: Enable Receiver Address interrupt.
Bit 2 = RXB:
Receiver Break Mask.
0: Disable Receiver Break interrupt (RXBP pend-
ing bit in the S_ISR register).
1: Enable Receiver Break interrupt.
Bit 1 = RXDI:
Receiver Data Interrupt Mask.
0: Disable Receiver Data Pending and Receiver
End of Block interrupts (RXDP and RXEOB
pending bits in the S_ISR register).
1: Enable Receiver Data Pending and Receiver
End of Block interrupts.
Note: RXDI has no effect on DMA transfers.
Bit 0 = TXDI:
Transmitter Data Interrupt Mask.
0: Disable Transmitter Buffer Register Empty,
Transmitter Shift Register Empty, or Transmitter
End of Block interrupts (TXBEM, TXSEM, and
TXEOB bits in the S_ISR register).
1: Enable Transmitter Buffer Register Empty,
Transmitter Shift Register Empty, or Transmitter
End of Block interrupts.
Note: TXDI has no effect on DMA transfers.
70
BSN
RXEOB TXEOB
RXE
RXA
RXB
RXDI
TXDI