Interrupt Sources; Interrupts In Normal Serial Communication Interface Mode - Renesas H8S/2100 Series Hardware Manual

Section 15 Serial Communication Interface (SCI)
15.8

Interrupt Sources

15.8.1

Interrupts in Normal Serial Communication Interface Mode

Table 15.13 shows the interrupt sources in normal serial communication interface mode. 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.
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.
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 15.13 SCI Interrupt Sources
Channel Name
1 ERI1
RXI1
TXI1
TEI1
2 ERI2
RXI2
TXI2
TEI2
Rev. 1.00 Apr. 28, 2008 Page 460 of 994
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Interrupt Source
Receive error
Receive data full
Transmit data empty
Transmit end
Receive error
Receive data full
Transmit data empty
Transmit end
Interrupt Flag
ORER, FER, PER
RDRF
TDRE
TEND
ORER, FER, PER
RDRF
TDRE
TEND
Priority
High
Low