Datasheet

Section 15 Serial Communication Interface (SCI and IrDA)

Rev. 3.00 Mar 21, 2006 page 405 of 788

REJ09B0300-0300

15.8 Interrupt Sources

Table 15.11 shows the interrupt sources in serial communication interface. A different interrupt

vector is assigned to each interrupt source, and individual interrupt sources can be enabled or

disabled using the enable bits in SCR.

When the TDRE flag in SSR is set to 1, a TXI interrupt request is generated. When the TEND flag

in SSR is set to 1, a TEI interrupt request is generated. A TXI interrupt can activate the DTC to

allow data transfer. The TDRE flag is automatically cleared to 0 at data transfer by the DTC.

When the RDRF flag in SSR is set to 1, an RXI interrupt request is generated. When the ORER,

PER, or FER flag in SSR is set to 1, an ERI interrupt request is generated. An RXI interrupt can

activate the DTC to allow data transfer. The RDRF flag is automatically cleared to 0 at data

transfer by the DTC.

A TEI interrupt is requested when the TEND flag is set to 1 while the TEIE bit is set to 1. If a TEI

interrupt and a TXI interrupt are requested simultaneously, the TXI interrupt has priority for

acceptance. However, note that if the TDRE and TEND flags are cleared simultaneously by the

TXI interrupt routine, the SCI cannot branch to the TEI interrupt routine later.

Table 15.11 SCI Interrupt Sources

Channel Name Interrupt Source Interrupt Flag DTC Activation Priority

ERI0 Receive error ORER, FER, PER Not possible High

RXI0 Receive data full RDRF Possible

TXI0 Transmit data empty TDRE Possible

TEI0 Transmit end TEND Not possible

ERI1 Receive error ORER, FER, PER Not possible

RXI1 Receive data full RDRF Possible

TXI1 Transmit data empty TDRE Possible

TEI1 Transmit end TEND Not possible

ERI2 Receive error ORER, FER, PER Not possible

RXI2 Receive data full RDRF Possible

TXI2 Transmit data empty TDRE Possible

TEI2 Transmit end TEND Not possible Low