RX - 8581 SA / JE / NB

8.2.8. Calendar counter (Reg 4 to 6)

Address

Function

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

 

 

 

 

 

 

 

 

 

 

4

DAY

!

!

20

10

8

4

2

1

5

MONTH

!

!

!

10

8

4

2

1

6

YEAR

80

40

20

10

8

4

2

1

∗) "o" indicates write-protected bits. A zero is always read from these bits.

•The auto calendar function updates all dates, months, and years from January 1, 2001 to December 31, 2099.

•The data format is BCD format. For example, a date register value of "0011 0001" indicates the 31st.

∗ Note with caution that writing non-existent date data may interfere with normal operation of the calendar counter. 1) Date counter

Address

Function

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

 

 

 

 

 

 

 

 

 

 

4

DAY

!

!

20

10

8

4

2

1

• The updating of dates by the date counter varies according to the month setting.

∗ A leap year is set whenever the year value is a multiple of four (such as 04, 08, 12, 88, 92, or 96). In February of a leap year, the counter counts dates from "01," "02," "03," to "28," "29," "01," etc.

 

 

 

 

 

 

DAY

 

 

Month

 

 

Date update pattern

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1, 3, 5, 7, 8, 10, or 12

 

 

01, 02, 03 ∼

30, 31, 01 ∼

 

 

 

 

 

 

 

Write/Read

 

4, 6, 9, or 11

 

 

01, 02, 03 ∼

30, 01, 02 ∼

 

 

 

 

 

 

 

 

February in normal year

 

01, 02, 03 ∼

28, 01, 02 ∼

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

February in leap year

 

 

01, 02, 03 ∼

28, 29, 01 ∼

 

 

2) Month counter

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Address

 

Function

 

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5

 

MONTH

!

!

!

10

8

 

 

4

 

2

1

 

 

•

The month counter counts from 01 (January), 02 (February), and up to 12 (December), then starts again

 

 

at 01 (January).

 

 

 

 

 

 

 

 

 

 

 

 

 

3) Year counter

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Address

 

Function

 

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6

 

Years

 

Y80

Y40

Y20

Y10

Y8

Y4

Y2

Y1

 

 

•

The year counter counts from 00, 01, 02 and up to 99, then starts again at 00.

 

 

 

 

 

 

 

•

Any year that is a multiple of four (04, 08, 12, 88, 92, 96, etc.) is handled as a leap year.

 

 

8.2.9. Alarm registers (Reg - 8 ∼ A)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Address

 

Function

 

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8

 

 

 

MIN Alarm

 

AE

40

20

10

8

 

 

4

 

2

1

 

9

 

 

HOUR Alarm

 

AE

•

20

10

8

 

 

4

 

2

1

 

A

 

WEEK Alarm

 

AE

6

5

4

3

 

 

2

 

1

0

 

 

 

DAY Alarm

 

•

20

10

8

 

 

4

 

2

1

 

 

 

 

 

 

 

 

 

 

•The alarm interrupt function is used, along with the AEI, AF, and WADA bits, to set alarms for specified date, day, hour, and minute values.

•When the settings in the above alarm registers and the WADA bit match the current time, the /INT pin goes to low level and "1" is set to the AF bit to report that and alarm interrupt event has occurred.

 

∗ For details, see "8.5. Alarm Interrupt Function".

 

 

 

 

 

 

 

8.2.10. Fixed-cycle timer control registers (Reg - B ∼

C)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Address

Function

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B

Timer Counter 0

128

64

32

16

8

4

2

1

 

 

C

Timer Counter 1

•

•

•

•

2048

1024

512

256

 

•

These registers are used to set the preset countdown value for the fixed-cycle timer interrupt function.

 

 

 

The TE, TF, TIE, and TSEL0/1 bits are also used to set the fixed-cycle timer interrupt function.

 

 

 

•

When the value in the above fixed-cycle timer control register changes from 001h to 000h, the /INT pin goes to

 

low level and "1" is set to the TF bit to report that a fixed-cycle timer interrupt event has occurred.

 

 

 

∗

For details, see "8.3. Fixed-cycle Timer Interrupt Function".

 

 

 

 

 

 

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