eZ80L92 MCU
Product Specification
103
CLK_SEL and FREQ_SEL select the RTC clock source. If the 32 kHz crystal option is
selected the oscillator is enabled and the internal prescaler is set to divide by 32768. If the
power-line frequency option is selected, the prescale value is set by FREQ_SEL, and the
32 kHz oscillator is disabled. See Table 51.
Table 51. Real Time Clock Control Register (RTC_CTRL = 00EDh)
Bit
7
X
R
6
0
5
X
4
X
3
X
2
X
R
1
0/1
R
0
0
Reset
CPU Access
R/W
R/W
R/W
R/W
R/W
Note: X = Unchanged by RESET; R = Read-only; R/W = Read/Write.
Bit
Position
Value Description
7
0
1
0
1
0
1
Alarm interrupt is inactive.
ALARM
Alarm interrupt is active.
6
Interrupt on alarm condition is disabled.
Interrupt on alarm condition is enabled.
INT_EN
5
RTC count and alarm value registers are binary.
BCD_EN
RTC count and alarm value registers are binary-coded
decimal (BCD).
4
0
1
RTC clock source is crystal oscillator output (32768 Hz).
On-chip 32768 Hz oscillator is enabled.
CLK_SEL
RTC clock source is power-line frequency input.
On-chip 32768 Hz oscillator is disabled.
3
0
1
0
0
1
0
Power-line frequency is 60Hz.
FREQ_SEL
Power-line frequency is 50Hz.
2
Reserved.
1
RTC does not generate a Sleep-Mode Recovery reset.
RTC Alarm generates a Sleep-Mode Recovery reset.
SLP_WAKE
0
RTC count registers are locked to prevent write access.
RTC counter is enabled.
RTC_UNLOCK
1
RTC count registers are unlocked to allow write access.
RTC counter is disabled.
PS013015-0316
Real Time Clock Alarm
ZILOG [ ZILOG, INC. ]
