R01UH0823EJ0100 Rev.1.00
Page 767 of 1823
Jul 31, 2019
RX23W Group
28. Realtime Clock (RTCe)
28.2.4
Hour Counter (RHRCNT)/Binary Counter 2 (BCNT2)
(1) In calendar count mode:
The RHRCNT counter is used for setting and counting the BCD-coded hour value. It counts carries generated once per
hour in the minute counter.
The specifiable time differs according to the setting in the hours mode bit (RCR2.HR24).
When the RCR2.HR24 bit is 0: From 00 to 11 (in BCD)
When the RCR2.HR24 bit is 1: From 00 to 23 (in BCD)
If a value outside of this range is specified, the RTC does not operate correctly. Before writing to this register, be sure to
stop the count operation through the setting of the START bit in RCR2.
The PM bit is only enabled when the RCR2.HR24 bit is 0. Otherwise, the setting in the PM bit has no effect.
After writing to the RHRCNT counter, confirm that its value has actually changed before proceeding with further
processing. Refer to
section 28.6.5, Notes When Writing to and Reading from Registers
for notes on accessing
registers.
(2) In binary count mode:
The BCNT2 counter is a readable/writable 32-bit binary counter b23 to b16.
The 32-bit binary counter performs count operation by a carry generating for each second of the 64-Hz counter.
Before writing to this register, be sure to stop the count operation through the setting of the START bit in RCR2.
To read this counter, follow the procedure in
section 28.3.5, Reading 64-Hz Counter and Time
.
Address(es): RTC.RHRCNT 0008 C406h
b7
b6
b5
b4
b3
b2
b1
b0
—
PM
HR10[1:0]
HR1[3:0]
Value after reset:
x
x
x
x
x
x
x
x
x: Undefined
Bit
Symbol
Bit Name
Description
R/W
b3 to b0
1-Hour Count
Counts from 0 to 9 once per hour. When a carry is generated, 1 is
added to the tens place.
R/W
b5, b4
10-Hour Count
Counts from 0 to 2 once per carry from the ones place.
R/W
b6
PM
Time Counter Setting for a.m./p.m.
0: a.m.
1: p.m.
R/W
b7
—
Reserved
Set this bit to 0. It is read as the set value.
R/W
Address(es): RTC.BCNT2 0008 C406h
b7
b6
b5
b4
b3
b2
b1
b0
BCNT[23:16]
Value after reset:
x
x
x
x
x
x
x
x
x: Undefined