M16C6K9 Datasheet, PDF (176/292 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6K9 Group
Serial Interrupt Output
q Operation mode
Fig.SI-9 shows an example of timing of continuous mode, Fig.SI-10 shows that of quiet mode.
➀Continuous mode
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After reset, at the rising edge of PRST (or LRESET) or the length of the last stop frame of serial
interrupt cycle being 3 clock cycles, it will be the continuous mode.
After receiving the start frame (Note 1), the Frame 1, Frame 12 or frames selected in each chan-
nel will be asserted.
Note 1: If the length of “L” is less than 4 clock cycles or more than 9 clock cycles, the start frame
will not be detected and the next start (the falling edge of SERIRQ) is waited.
Start frame (Note1)
IRQ0 frame
IRQ1 frame
IRQ2 frame
IRQ3 frame
Clock
SERIRQ line
System•SERIRQ output
Device•SERIRQ output
Driver source
System side
Device side
Note1 . The start frame is set to 4 clock as setting exemple
Fig.SI-9 Timing diagram of continuous mode
➁Quiet mode
At clock stop or clock slow down, or the length of the last stop frame of serial interrupt cycle being
2 clock cycles, it will be the quiet mode.
In this mode the SERIRQ is driven to “L” in the 1^st clock cycle by device and after the receiving of
the rest start frame (Note 1) from host, the IRQ1 Frame , IRQ12 Frame or frames selected in each
channel will be asserted.
Note 1: If the sum of length of “L” that is driven by the device in the 1^st clock cycle and by the host
in the rest clock cycles is within 4-8 clock cycles, the start frame will be detected.
If the sum of length of “L” is less than 4 clock cycles or more than 9 clock cycles, the start
frame will not be detected and the next start (the falling edge of SERIRQ) is waited.
LCLK
SERIRQ line
System•SERIRQ output
Device•SERIRQ output
Driver source
Start frame (Note1)
Device side
System side
IRQ0 frame
IRQ1 frame
IRQ2 frame
IRQ3 frame
Device side
Note1 . The start frame is set to 4 clock as setting example
Fig.SI-10 Timing diagram of quiet mode
Rev.1.00 Jun 06, 2003 page 176 of 290