RX610 Group
20. Serial Communications Interface (SCI)
R01UH0032EJ0120 Rev.1.20
Page 672 of 1006
Feb 20, 2013
20.6
Interrupt Sources
20.6.1
Interrupts in Serial Communications Interface Mode
Table 20.15 lists interrupt sources in normal serial communications interface mode. A different interrupt vector is
assigned to each interrupt source, and individual interrupt sources can be enabled or disabled with the enable bits in SCR.
Transfer of data from the transmit data register (TDR) to the TSR while the SCR.TIE bit is 1 leads to the generation of a
TXI interrupt request. Moreover, setting the TIE bit in SCR to 1 and then setting the TE bit to 1, or setting the TIE and
TE bits in SCR to 1 simultaneously using one instruction, leads to the generation of a TXI interrupt request. A TXI
interrupt request can activate the DTC or DMAC for data transfer.
Setting of received data in the RDR while the SCR.RIE bit is 1 leads to the generation of an RXI interrupt request. An
RXI interrupt can activate the DTC or DMAC for data transfer.
Setting the ORER, FER, or PER flag in the SSR to 1 while the SCR.RIE bit is 1 leads to generation of an ERI interrupt
request.
If the TDR has not been updated by the time of transmission of the tail-end bit of data being transmitted, the SSR.TEND
flag is set to 1 and, if the value of the SCR.TEIE bit is 1, a TEI interrupt request is generated. Writing of data to the TDR
during TXI interrupt processing leads to clearing of the SSR.TEND flag and clearing of the TEI interrupt at its source.
The TXI interrupt request is generated by setting the TIE bit in SCR to 1 and then setting the TE bit to 1 or by setting the
TIE and TE bits in SCR to 1 simultaneously using one instruction. The TXI interrupt is not generated if the TE bit is set
while the TIE bit is 0 or the TIE bit is set to 1 after the TE bit is set to 1. Therefore, to disable the TXI interrupt, perform
the transmit end interrupt processing, and then start data transfer again, for example, in the final data transmission, the
TXI interrupt should be enabled/disabled using the corresponding ICU.IERm.IENj bit.
Table 20.15 SCI Interrupt Sources
Name
Interrupt Source
Interrupt Flag
DTC Activation
DMAC Activation
Priority
ERI
Receive error
ORER, FER, or PER
Not possible
Not possible
High
RXI
Receive data full
Possible
Possible
TXI
Transmit data empty
Possible
Possible
TEI
Transmit end
TEND
Not possible
Not possible
Low
Summary of Contents for RX600 Series
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