Interrupts In Smart Card Interface Mode - Renesas RZ/A Series User Manual

RZ/A1L Group, RZ/A1LU Group, RZ/A1LC Group
15.8.2

Interrupts in Smart Card Interface Mode

Table 15.17 lists interrupt sources in smart card interface mode. A transmit end interrupt (TEI) request cannot be used in
this mode.
Table 15.17 Interrupt Sources
Name Interrupt Source
ERI Receive error or error signal detection
RXI Receive data full
TXI Transmit data empty
Data transmission/reception using the DMAC is also possible in smart card interface mode. In transmission, when the
TEND flag in SSR is set to 1, a TXI interrupt request is generated. This TXI interrupt request activates the DMAC
allowing transfer of transmit data if the TXI request is specified beforehand as a source of DMAC activation. The TEND
flag in SSR is automatically cleared to 0 when the DMAC transfers the data.
If an error occurs, the SCI automatically re-transmits the same data. During the retransmission, the TEND flag in SSR is
kept to 0 and the DMAC is not activated. Therefore, the SCI and DMAC automatically transmit the specified number of
bytes, including retransmission in the case of error occurrence. However, the ERS flag in SSR is not automatically
cleared to 0 at error occurrence. Therefore, the ERS flag in SSR must be cleared by previously setting the RIE bit in SCR
to 1 to enable an ERI interrupt request to be generated at error occurrence.
When transmitting/receiving data using the DMAC, be sure to make settings to enable the DMAC before making SCI
settings. For DMAC settings, see section 9, Direct Memory Access Controller.
In reception, an RXI interrupt request is generated when receive data is set to RDR. This RXI interrupt request activates
the DMAC allowing transfer of receive data if the RXI request is specified beforehand as a source of DMAC activation.
If an error occurs, the error flag is set. Therefore, the DMAC is not activated and an ERI interrupt request is issued to the
CPU instead; the error flag must be cleared.
R01UH0437EJ0600 Rev.6.00
Jan 29, 2021
15. Serial Communications Interface
Interrupt Flag
ORER, PER, or ERS
—
TEND
DMAC Activation
Not possible
Possible
Possible
15-60