M16C28 Datasheet, PDF (385/423 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/Tiny SERIES

M16C/28 Group (M16C/28, M16C/28B)
20. Precautions
20.7 Timer S
20.7.1 Rewrite the G1IR Register
Bits in the G1IR register are not automatically set to 0 (no interrupt requested) even if a requested inter-
rupt is acknowledged. Set each bit to 0 by program after the interrupt requests are verified.
The IC/OC interrupt is generated when any bit in the G1IR register is set to 1 (interrupt requested) after all
the bits are set to 0. If conditions to generate an interrupt are met when the G1IR register holds the value
other than 0016, the IC/OC interrupt request will not be generated. In order to enable an IC/OC interrupt
request again, clear the G1IR register to 0016. Use the following instructions to set each bit in the G1IR
register to 0.
Subject instructions: AND, BCL
Figure 20.4 shows an example of IC/OC interrupt i processing.
Interrupt⁽¹⁾
G1IRi=1 ?
No
Yes
Set the G1IRi bit to "0"
Process channel i waveform generating interrupt
G1IRj=1 ?
No
Yes
Set the G1IRj bit to "0"
Process channel j time measurement interrupt
No
G1IR=0 ?
Yes
Interrupt completed
NOTES:
1. Example for the interrupt operation when using the channel i waveform generating interrupt and
channel j time measurement interrupt.
Figure 20.4 IC/OC Interrupt i Flow Chart
Rev. 2.00 Jan. 31, 2007 ^{page 365} of 385
REJ09B0047-0200