R01UH0823EJ0100 Rev.1.00
Page 772 of 1823
Jul 31, 2019
RX23W Group
28. Realtime Clock (RTCe)
28.2.9
Second Alarm Register (RSECAR)/Binary Counter 0 Alarm Register
(BCNT0AR)
(1) In calendar count mode:
The RSECAR register is an alarm register corresponding to the BCD-coded second counter RSECCNT. When the ENB
bit is set to 1, the RSECAR value is compared with the RSECCNT value. From among the alarm registers (RSECAR,
RMINAR, RHRAR, RWKAR, RDAYAR, RMONAR, and RYRAREN), only those selected with the ENB bits set to 1
are compared with the corresponding counters. When the respective values all match, the IR flag corresponding to the
ALM interrupt is set to 1.
RSECAR values from 00 through 59 (in BCD) can be specified; if a value outside of this range is specified, the RTC
does not operate correctly.
After writing to the RSECAR register, 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.
This register is set to 00h by an RTC software reset.
(2) In binary count mode:
The BCNT0AR counter is a readable/writable alarm register corresponding to 32-bit binary counter b7 to b0.
This register is set to 00h by an RTC software reset.
Address(es): RTC.RSECAR 0008 C410h
b7
b6
b5
b4
b3
b2
b1
b0
ENB
SEC10[2:0]
SEC1[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 Second
Value for the ones place of seconds
R/W
b6 to b4
10 Seconds
Value for the tens place of seconds
R/W
b7
ENB
0: The register value is not compared with the RSECCNT counter value.
1: The register value is compared with the RSECCNT counter value.
R/W
Address(es): RTC.BCNT0AR 0008 C410h
b7
b6
b5
b4
b3
b2
b1
b0
BCNTAR[7:0]
Value after reset:
x
x
x
x
x
x
x
x
x: Undefined