8 REAL-TIME CLOCK (RTC)
8-18
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
RTC Days of Week Register (RTC_WEEK)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
RTC Days of
Week Register
(RTC_WEEK)
0x300a0a
(8 bits)
D7–3 –
reserved
–
–
–
0 when being read.
D2–0 RTCWK[2:0] RTC days of week counter
RTCWK[2:0]
Days of week X (
*
) R/W
0x7
0x6
0x5
0x4
0x3
0x2
0x1
0x0
–
Saturday
Friday
Thursday
Wednesday
Tuesday
Monday
Sunday
*
Software reset (RTCRST
→
1
→
0) does not affect the counter values. This register retains the value set before a software reset is
performed.
Notes: • Data should not be read from or written to the counters while 1 is being carried over. (See
Section 8.3.5, “Counter Hold and Busy Flag,” and Section 8.3.7, “Counter Read.”)
• Rewriting RTC24H/RTC_CNTL0 register may corrupt the count data in this register. Therefore,
after changing the RTC24H setting, be sure to set up this register again.
D[7:3]
Reserved
D[2:0]
RTCWK[2:0]: RTC Days of Week Counter Bits
These bits are the septenary counter (that counts from 0 to 6) bits representing days of the week. This
counter counts at the same timing as the 1-day counter.
The correspondence between the counter values and days of the week can be set in a program as de-
sired. Table 8.6.3 lists the basic correspondence.
6.3 Correspondence between Counter Values and Days of the Week
Table 8.
RTCWK[2:0]
Days of the week
0x6
Saturday
0x5
Friday
0x4
Thursday
0x3
Wednesday
0x2
Tuesday
0x1
Monday
0x0
Sunday
(Default: indeterminate, software reset: previous value retained)
RTC Wakeup Configuration Register (RTC_WAKEUP)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
RTC Wakeup
Configuration
Register
(RTC_WAKEUP)
0x300a0f
(8 bits)
D7–2 –
reserved
–
–
–
0 when being read.
D1
WUP_CTL WAKEUP control
1 Active
0 Inactive
X (0) R/W
D0
WUP_POL WAKEUP polarity select
1 Active low
0 Active high X (0) R/W
Init.: ( ) indicates the value set after a software reset (RTCRST
→
1
→
0) is performed.
D[7:2]
Reserved
D1
WUP_CTL: WAKEUP Control Bit
This bit controls the WAKEUP output.
1 (R/W): Active
0 (R/W): Inactive (software reset value)
This bit is used to control the WAKEUP output with software. The WAKEUP signal will also be as-
serted when a cause of RTC interrupt occurs.
D0
WUP_POL: WAKEUP Polarity Select Bit
This bit selects the active level of the WAKEUP output signal.
1 (R/W): Active low
0 (R/W): Active high (software reset value)