HD64F38602R Datasheet, PDF (306/552 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Section 14 Serial Communication Interface 3 (SCI3, IrDA)
14.7 Interrupt Requests
The SCI3 creates the following six interrupt requests: transmit end, transmit data empty, receive
data full, and receive errors (overrun error, framing error, and parity error). Table 14.13 shows the
interrupt sources.
Table 14.13 SCI3 Interrupt Requests
Interrupt Requests
Receive Data Full
Transmit Data Empty
Transmission End
Receive Error
Abbreviation
RXI
TXI
TEI
ERI
Interrupt Sources
Setting RDRF in SSR
Setting TDRE in SSR
Setting TEND in SSR
Setting OER, FER, and PER in SSR
Each interrupt request can be enabled or disabled by means of bits TIE and RIE in SCR.
When the TDRE bit in SSR is set to 1, a TXI3 interrupt is requested. When the TEND bit in SSR
is set to 1, a TEI3 interrupt is requested. These two interrupts are generated during transmission.
The initial value of the TDRE flag in SSR is 1. Thus, when the TIE bit in SCR is set to 1 before
transferring the transmit data to TDR, a TXI3 interrupt request is generated even if the transmit
data is not ready. The initial value of the TEND flag in SSR is 1. Thus, when the TEIE bit in SCR
is set to 1 before transferring the transmit data to TDR, a TEI3 interrupt request is generated even
if the transmit data has not been sent. It is possible to make use of the most of these interrupt
requests efficiently by transferring the transmit data to TDR in the interrupt routine. To prevent
the generation of these interrupt requests (TXI3 and TEI3), clear the enable bits (TIE and TEIE)
that correspond to these interrupt requests to 0, after transferring the transmit data to TDR.
When the RDRF bit in SSR is set to 1, an RXI3 interrupt is requested, and if any of bits OER,
PER, and FER is set to 1, an ERI3 interrupt is requested. These two interrupt requests are
generated during reception.
The SCI3 can carry out continuous reception using an RXI3 and continuous transmission using a
TXI3.
Rev. 3.00 May 15, 2007 Page 274 of 516
REJ09B0152-0300