Year Counter (Ryrcnt); Second Alarm Register (Rsecar) - Hitachi SH7709S Hardware Manual

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13.2.8

Year Counter (RYRCNT)

The year counter (RYRCNT) is an 8-bit readable/writable register used for setting/counting in the
BCD-coded year section of the RTC. The least significant 2 digits of the western calendar year are
displayed. The count operation is performed by a carry for each year of the month counter.
The range that can be set is 00–99 (decimal). Errant operation will result if any other value is set.
Carry out write processing after halting the count operation with the START bit in RCR2.
RYRCNT is not initialized by a power-on reset or manual reset, or in standby mode.
Leap years are recognized by dividing the year counter value by 4 and obtaining a fractional result
of 0. The year counter value: 00 is included in leap years.
Bit:
Initial value:
R/W:
R/W
13.2.9

Second Alarm Register (RSECAR)

The second alarm register (RSECAR) is an 8-bit readable/writable register, and an alarm register
corresponding to the BCD-coded second section counter RSECCNT of the RTC. When the ENB
bit is set to 1, a comparison with the RSECCNT value is performed. From among the
RSECAR/RMINAR/RHRAR/RWKAR/RDAYAR/RMONAR registers, the counter and alarm
register comparison is performed only on those with ENB bits set to 1, and if each of those
coincide, an RTC alarm interrupt is generated.
The range that can be set is 00–59 (decimal) + ENB bit. Errant operation will result if any other
value is set.
The ENB bit in RSECAR is initialized to 0 by a power-on reset. The remaining RSECAR fields
are not initialized and retain their contents by a manual reset, or in standby mode.
Bit:
ENB
Initial value:
R/W:
R/W
7
6
5
10 years
R/W
R/W
7
6
5
10 seconds
0
R/W
R/W
4
3
2
1 year
R/W
R/W
R/W
4
3
2
1 second
R/W
R/W
R/W
1
0
R/W
R/W
1
0
R/W
R/W
419

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