SH7720 Datasheet, PDF (697/1524 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 18 Serial Communication Interface with FIFO (SCIF)
18.5 Interrupt Sources and DMAC
In asynchronous mode, the SCIF supports six interrupts: transmit-FIFO-data-empty, transmit data
stop, receive-error, receive-FIFO-data-full, break receive, and receive data ready. A common
interrupt vector is assigned to each interrupt source.
In synchronous mode, the SCIF supports two interrupts: transmit-FIFO-data-empty and receive-
FIFO-data-full.
Table 18.4 shows the interrupt sources. The interrupt sources are enabled or disabled by means of
the TIE, RIE, ERIE, BRIE, DRIE, and TSIE bits in SCSCR.
When the TDFE flag in SCSSR is set to 1, the transmit-FIFO-data-empty interrupt request is
generated. When the TSF flag in SCSSR is set to 1, the transmit-data-stop interrupt request is
generated. Activating the DMAC and transferring data can be performed by the transmit-FIFO-
data-empty interrupt and data stop interrupt requests. The DMAC transfer request is automatically
cleared when the number of data written to SCFTDR by the DMAC is increased more than that of
setting transmit triggers.
When the RDF flag in SCSSR is set to 1, a receive-FIFO-data-full interrupt request is generated.
Activating the DMAC and transferring data can be performed by the receive-FIFO-data-full
interrupt request. The DMAC transfer request is automatically cleared when receive data is read
from SCFRDR by the DMAC until the number of receive data in SCFRDR is decreased less than
that of receive triggers.
When executing the data transmission and reception, set the DMAC, and then set SCIF after
entered in the enabled state. The completion of the DMA transfer is the completion of
transmission and reception. For the DMAC setting procedure, see section 10, Direct Memory
Access Controller (DMAC).
An interrupt request is generated when the ER flag in SCSSR is set to1; the BRK flag in SCSSR is
set to 1; the DR flag in SCSSR is set to 1; or the TSF flag in SCSSR is set to 1. A common
interrupt vector is assigned to each interrupt source. The activation of DMAC and generation of an
interrupt are not executed at the same time by the same source. When activating the DMAC, carry
out the following procedure.
• Set the interrupt enable bits (TIE, RIE) that correspond to the interrupt sources used for
activation of the DMAC. Clear the other interrupt enable bits (TSIE, ERIE, BRIE, and DRIE)
to 0.
Rev. 3.00 Jan. 18, 2008 Page 635 of 1458
REJ09B0033-0300