HD6417706 RENESAS [Renesas Technology Corp], HD6417706 Datasheet - Page 388

• Manufacturer Part Number: HD6417706
• Description: Renesas 32-Bit RISC Microcomputer Super RISC engine Family/SH7700 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

13.4.3
Figure 13.3 shows how to read the time. If a carry occurs while reading the time, the correct time
will not be obtained, so it must be read again. Part (a) in figure 13.3 shows the method of reading
the time without using interrupts; part (b) in figure 13.3 shows the method using carry interrupts.
To keep programming simple, method (a) should normally be used.
Rev. 4.00, 03/04, page 342 of 660
Reading the Time
Yes
Yes
(a)
(b) To use interrupts
Clear the carry flag
Clear the carry flag
Disable the carry
To read the time
without using interrupts
Disable the carry
Enable the carry
Carry flag = 1?
Read counter
Read counter
generated?
Figure 13.3 Reading the Time
Interrupt
interrupt
interrupt
register
register
interrupt
No
No
Write 0 to CIE in RCR1
Write 0 to CF in RCR1
Note: Set AF in RCR1 to 1 so that
Read RCR1 and check CF
Write 1 to CIE in RCR1,
and write 0 to CF in RCR1
Note: Set AF in RCR1 to 1 so that
Write 0 to CIE in RCR1
alarm flag is not cleared.
alarm flag is not cleared.