UM10850
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2016. All rights reserved.
User manual
Rev. 2.4 — 13 September 2016
234 of 464
NXP Semiconductors
UM10850
Chapter 16: LPC5410x Real-Time Clock (RTC)
16.6.2 RTC match register
16.6.3 RTC counter register
4
ALARMDPD_EN
RTC 1 Hz timer alarm enable for Deep power-down.
0
0
Disable. A match on the 1 Hz RTC timer will not bring the part out of Deep
power-down mode.
1
Enable. A match on the 1 Hz RTC timer bring the part out of Deep power-down
mode.
5
WAKEDPD_EN
RTC 1 kHz timer wake-up enable for Deep power-down.
0
0
Disable. A match on the 1 kHz RTC timer will not bring the part out of Deep
power-down mode.
1
Enable. A match on the 1 kHz RTC timer bring the part out of Deep power-down
mode.
6
RTC1KHZ_EN
RTC 1 kHz clock enable.
This bit can be set to 0 to conserve power if the 1 kHz timer is not used. This bit has
no effect when the RTC is disabled (bit 7 of this register is 0).
0
0
Disable. A match on the 1 kHz RTC timer will not bring the part out of Deep
power-down mode.
1
Enable. The 1 kHz RTC timer is enabled.
7
RTC_EN
RTC enable.
0
0
Disable. The RTC 1 Hz and 1 kHz clocks are shut down and the RTC operation is
disabled. This bit should be 0 when writing to load a value in the RTC counter
register.
1
Enable. The 1 Hz RTC clock is running and RTC operation is enabled. This bit must
be set to initiate operation of the RTC. The first clock to the RTC counter occurs 1 s
after this bit is set. To also enable the high-resolution, 1 kHz clock, set bit 6 in this
register.
31:8 -
Reserved. Read value is undefined, only zero should be written.
0
Table 276. RTC control register (CTRL, address 0x4003 C000) bit description
Bit
Symbol
Value Description
Reset
value
Table 277. RTC match register (MATCH, address 0x4003 C004) bit description
Bit
Symbol
Description
Reset value
31:0
MATVAL
Contains the match value against which the 1 Hz RTC timer will be compared to generate
set the alarm flag RTC_ALARM and generate an alarm interrupt/wake-up if enabled.
0xFFFF
Table 278. RTC counter register (COUNT, address 0x4003 C008) bit description
Bit
Symbol
Description
Reset value
31:0
VAL
A read reflects the current value of the main, 1 Hz RTC timer.
A write loads a new initial value into the timer.
The RTC counter will count up continuously at a 1 Hz rate once the RTC Software Reset is
removed (by clearing bit 0 of the CTRL register).
Remark:
Only write to this register when the RTC_EN bit in the RTC CTRL Register is 0.
The counter increments one second after the RTC_EN bit is set.
0