Epson S1C17624 Technical Manual page 83

Also be sure to write 1 to RTCIRQ to reset it.
When a software reset is performed (RTCRST → 1 → 0), RTCIRQ and RTCIEN are reset to 0 to disable the
interrupt request output. Also RTCT[2:0] is reset to 0x1.
8.5 Details of Control Registers
address
0x506e RTC_CC
0x5140 RTC_INTSTAT
0x5141 RTC_INTMODE
0x5142 RTC_CNTL0
0x5143 RTC_CNTL1
0x5144 RTC_SEC
0x5145 RTC_MIN
0x5146 RTC_HOUR
0x5147 RTC_DAY
0x5148 RTC_MONTH
0x5149 RTC_YEAR
0x514a RTC_WEEK
The following describes each RTC register. These are all 8-bit registers.
notes: • When data is written to the register, the "Reserved" bits must always be written as 0 and not 1.
• The contents of all RTC control registers are indeterminate when power is turned on, and are
not initialized to specific values by initial reset. These registers should be initialized in software.
• If 1 is being carried over when the counters are accessed for read, the correct counter value
may not be read out. Moreover, attempting to write to a counter or other control register may
corrupt the counter value. Therefore, do not write to counters while 1 is being carried over. For
the correct method of operation, see Section 8.3.5, "Counter Hold and Busy Flag," and Section
8.3.7, "Counter Read."
RTC Clock Control Register (RTC_CC)
Register name address Bit
RTC Clock 0x506e D7–1 –
Control Register (8 bits)
(RTC_CC)
D0
D[7:1] Reserved
D0 RTCCe: RTC Clock enable Bit
Enables or disables the OSC1 clock supply to the RTC.
1 (R/W): Enabled (on)
0 (R/W): Disabled (off) (default)
The RTCCE default setting is 0, which disables the clock supply. Setting RTCCE to 1 sends the OSC1
clock to the RTC. When the OSC1 oscillator circuit is stopped, writing 1 to RTCCE turns it on (note,
however, that the OSC1 clock is not supplied to other peripheral circuits than the RTC). When RTCCE
is set to 1, the OSC1 oscillator circuit does not stop even if the IC enters SLEEP mode (the OSC1 clock
will be supplied to the RTC only).
When RTCCE is set to 0, RTC interrupt requests generated by RTCIEN/RTC_INTMODE register and
RTCIRQ/RTC_INTSTAT register are masked to prevent occurrence of undesired interrupts.
S1C17624/604/622/602/621 TeChniCal Manual
Table 8. 5.1 RTC Register List
Register name
RTC Clock Control Register
RTC Interrupt Status Register
RTC Interrupt Mode Register
RTC Control 0 Register
RTC Control 1 Register
RTC Second Register
RTC Minute Register
RTC Hour Register
RTC Day Register
RTC Month Register
RTC Year Register
RTC Days of Week Register
name Function
reserved
RTCCe
RTC clock enable
Seiko epson Corporation
8 Real-TiMe ClOCK (RTC)
Function
Controls the RTC clock source.
Indicates RTC interrupt status.
Sets up RTC interrupt modes.
Controls the RTC.
Second counter data
Minute counter data
Hour counter data
Day counter data
Month counter data
Year counter data
Days of week counter data
Setting init. R/W
–
1 Enable 0 Disable
Remarks
– – 0 when being read.
0 R/W
8-9