CHAPTER 10 SERIAL INTERFACE FUNCTION
User’s Manual U15195EJ5V0UD
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10.2.4 Interrupt requests
The following three types of interrupt requests are generated from UART0.
•
Reception completion interrupt (INTSR0)
•
Transmission completion interrupt (INTST0)
•
Reception error interrupt (INTSER0)
The default priorities among these three types of interrupt requests is, from high to low, reception completion
interrupt, transmission completion interrupt, and reception error interrupt.
Table 10-1. Generated Interrupts and Default Priorities
Interrupt Priority
Reception completion
1
Transmission completion
2
Reception error
3
(1) Reception completion interrupt (INTSR0)
When reception is enabled, an INTSR0 signal is generated when data is shifted in to the receive shift register
and transferred to receive buffer register 0 (RXB0).
An INTSR0 signal can be generated in place of a reception error interrupt (INTSER0) according to the ISRM
bit of the ASIM0 register even when a reception error has occurred.
When reception is disabled, no INTSR0 signal is generated.
(2) Transmission completion interrupt (INTST0)
An INTST0 signal is generated when one frame of transmit data containing 7-bit or 8-bit characters is shifted
out from the transmit shift register.
(3) Reception error interrupt (INTSER0)
When reception is enabled, an INTSER0 signal is generated according to the logical OR of the three types of
reception errors explained for the ASIS0 register. Whether an INTSER0 signal or an INTSR0 signal is
generated when an error occurs can be specified using the ISRM bit of the ASIM0 register.
When reception is disabled, no INTSER0 signal is generated.