M16C65 Datasheet, PDF (446/829 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M16C/60

Under development
M16C/65 Group
Preliminary Specification
This is a preliminary specification and is subject to change.
20. Real-Time Clock
RTCRST (Real-Time Clock Reset Bit) (b4)
When setting this bit to 0 after setting it to 1, the following are set automatically.
• The values are reset in registers RTCSEC, RTCMIN, RTCHR, RTCWK, RTCCR2, RTCCSR,
RTCCSEC, RTCCMIN, and RTCCHR.
• Bits TCSTF, RTCPM, H12H24, and TSTART in the RTCCR1 register become 0.
RTCPM (A.M./P.M. Bit) (b5)
Write to the RTCPM bit when both bits TSTART and TCSTF in the RTCCR1 register are 0 (timer stops).
Read this bit when the BSY bit in the RTCSEC register is 0 (not while data is updated).
The RTCPM bit is enabled when the H12H24 bit is 0 (12-hour mode) or 1 (24-hour mode). Set the
RTCPM bit as below to set time while the H12H24 bit is 1.
• Set the RTCPM bit to 0 when bits HR11 to HR10 and HR03 to HR00 in the RTCHR register are 00
to 11.
• Set the RTCPM bit to 1 when bits HR11 to HR10 and HR03 to HR00 in the RTCHR register are 12
to 23.
The RTCPM bit changes as follows while counting.
• Becomes 0 when the RTCPM bit is 1 (p.m.) while the clock increments from 11:59:59 (23:59:59 for
24-hour mode) to 00:00:00.
• Becomes 1 when the RTCPM bit is 0 (a.m.) while the clock increments from 11:59:59 to 00:00:00
(12:00:00 for 24-hour mode).
Figure 20.2 shows Definition of Time Representation.
Noon
Contents
of
RTCHR
Register
H12H24 bit = 1
(24-hour mode)
H12H24 bit = 0
(12-hour mode)
Contents of RTCPM bit
Contents in RTCWK register
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
0 1 2 3 4 5 6 7 8 9 10 11 0 1 2 3 4 5
0 (a.m.)
000 (Day 1)
1 (p.m.)
Date changes
Contents
of
H12H24 bit = 1
(24-hour mode)
18 19 20 21 22 23 0 1 2 3
...
RTCHR
Register
H12H24 bit = 0
(12-hour mode)
6 7 8 9 10 11 0 1 2 3
...
Contents of RTCPM bit
1 (p.m.)
0 (a.m.)
...
Contents in RTCWK register
000 (Day 1)
001 (Day 2)
...
Bits RTCPM and H12H24 : Bits in the RTCCR1 register
The above applies to the case when count starts from 0 a.m.of day 1.
Figure 20.2 Definition of Time Representation
H12H24 (Operating Mode Select Bit) (b6)
Write to the H12H24 bit when both bits TSTART and TCSTF in the RTCCR1 register are 0 (timer
stops).
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
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