Hitachi H8S/2633 Hardware Manual page 703

requests, and receive data full interrupt (RXI) requests. The transmit end interrupt (TEI) request is

not used in this mode.

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

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

When any of flags ORER, PER, and ERS in SSR is set to 1, an ERI interrupt request is generated.

The relationship between the operating states and interrupt sources is shown in table 17-8.

Note: For block transfer mode, see section 16.4, SCI Interrupts.

Table 17-8 Smart Card Mode Operating States and Interrupt Sources

Operating State

Data Transfer Operation by DMAC or DTC: In smart card mode, as with the normal SCI,

transfer can be carried out using the DMAC or DTC. In a transmit operation, the TDRE flag is

also set to 1 at the same time as the TEND flag in SSR, and a TXI interrupt is generated. If the

TXI request is designated beforehand as a DMAC or DTC activation source, the DMAC or DTC

will be activated by the TXI request, and transfer of the transmit data will be carried out. The

TDRE and TEND flags are automatically cleared to 0 when data transfer is performed by the

DTC. In the event of an error, the SCI retransmits the same data automatically. During this period,

TEND remains cleared to 0 and the DMAC is not activated. Therefore, the SCI and DMAC will

automatically transmit the specified number of bytes, including retransmission in the event of an

error. However, the ERS flag is not cleared automatically when an error occurs, and so the RIE bit

should be set to 1 beforehand so that an ERI request will be generated in the event of an error, and

the ERS flag will be cleared.

When performing transfer using the DMAC or DTC, it is essential to set and enable the DMAC or

DTC before carrying out SCI setting. For details of the DMAC or DTC setting procedures, see

section 8, DMA Controller (DMAC) and section 9, Data Transfer Controller (DTC).

In a receive operation, an RXI interrupt request is generated when the RDRF flag in SSR is set to

1. If the RXI request is designated beforehand as a DMAC or DTC activation source, the DMAC

or DTC will be activated by the RXI request, and transfer of the receive data will be carried out.

The RDRF flag is cleared to 0 automatically when data transfer is performed by the DMAC or

Not possible

Not possible

DTC Activation

Not possible

Not possible