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Rev. 1.00
404 of 576
January 28, 2022
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F54231/HT32F54241/HT32F54243/HT32F54253
18 Real T
ime Clock (RTC)
Register Map
The following table shows the RTC registers and reset values. Note all the registers in this unit are
located at the V
DD
power domain.
Table 45. RTC Register Map
Register
Offset
Description
Reset Value
RTCCNT
0x000
RTC Counter Register
0x0000_0000
RTCCMP
0x004
RTC Compare Register
0x0000_0000
RTCCR
0x008
RTC Control Register
0x0000_0F00
RTCSR
0x00C
RTC Status Register
0x0000_0000
RTCIWEN
0x010
RTC Interrupt and Wakeup Enable Register
0x0000_0000
Register Descriptions
RTC Counter Register – RTCCNT
This register defines a 24-bit up-counter which is increased by the CK_SECOND clock.
Address:
0x000
Reset value: 0x0000_0000
31
30
29
28
27
26
25
24
Reserved
Type/Reset
23
22
21
20
19
18
17
16
RTCCNTV
Type/Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0
15
14
13
12
11
10
9
8
RTCCNTV
Type/Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0
7
6
5
4
3
2
1
0
RTCCNTV
Type/Reset RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0 RO 0
Bits
Field
Descriptions
[23:0]
RTCCNTV
RTC Counter Value
The current value of the RTC counter is returned when reading the RTCCNT register.
The RTCCNT register is updated during the falling edge of the CK_SECOND clock.
This register is reset by one of the following conditions:
- V
DD
Domain software reset – set the PWCURST bit in the PWRCR register
- V
DD
Domain power on reset – POR
- Compare match (RTCCNT = RTCCMP) when CMPCLR = 1 (in the RTCCR
register)
- RTCEN bit changed from 0 to 1