Interrupts; Interrupts In Normal Serial Communication Interface Mode; Figure 14.32 Clock Halt And Restart Procedure - Renesas H8S Series Hardware Manual

When returning to smart card interface mode from software standby mode:
1. Exit the software standby state.
2. Write 1 to the CKE0 bit in SCR and output the clock. Signal generation is started with the
normal duty.
Normal operation
[1] [2] [3]
14.8

Interrupts

14.8.1

Interrupts in Normal Serial Communication Interface Mode

Table 14.12 shows the interrupt sources in normal serial communication interface mode. A
different interrupt vector is assigned to each interrupt source, and individual interrupt sources can
be enabled or disabled using the enable bits in SCR.
When the TDRE flag in SSR is set to 1, a TXI interrupt request is generated. When the TEND flag
in SSR is set to 1, a TEI interrupt request is generated. A TXI interrupt can activate the DTC to
perform data transfer. The TDRE flag is cleared to 0 automatically when data is transferred by the
DTC.
When the RDRF flag in SSR is set to 1, an RXI interrupt request is generated. When the ORER,
PER, or FER flag in SSR is set to 1, an ERI interrupt request is generated. An RXI interrupt
request can activate the DTC to transfer data. The RDRF flag is cleared to 0 automatically when
data is transferred by the DTC.
A TEI interrupt is requested when the TEND flag is set to 1 and the TEIE bit is set to 1. If a TEI
interrupt and a TXI interrupt are requested simultaneously, the TXI interrupt has priority for
acceptance. However, if the TDRE and TEND flags are cleared simultaneously by the TXI
interrupt routine, the SCI cannot branch to the TEI interrupt routine later.
[4] [5]

Figure 14.32 Clock Halt and Restart Procedure

Section 14 Serial Communication Interface (SCI)
Software
Normal operation
standby
[6] [7]
Rev. 6.00 Mar 15, 2006 page 375 of 570
REJ09B0211-0600