Epson RX-8581JE, RX-8581NB, RX-8581SA 14

RX - 8581 SA / JE / NB

8.2.6. Clock counter (Reg - 0 ∼ 2)

Address	Function	bit 7	bit 6	bit 5	bit 4	bit 3	bit 2	bit 1	bit 0

0	SEC	!	40	20	10	8	4	2	1
1	MIN	!	40	20	10	8	4	2	1
2	HOUR	!	!	20	10	8	4	2	1

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

•The clock counter counts seconds, minutes, and hours.

•The data format is BCD format. For example, when the "seconds" register value is "0101 1001" it indicates 59 seconds.

∗ Note with caution that writing non-existent time data may interfere with normal operation of the clock counter.

1) Second counter

Address

Function

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

0

SEC

!

40

20

10

8

4

2

1

• This second counter counts from "00" to "01," "02," and up to 59 seconds, after which it starts again from

00 seconds.

• When data was written to seconds counter, the internal divider is reset from 2048Hz to 1Hz.

2) Minute counter

Address

Function

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

1

MIN

!

40

20

10

8

4

2

1

• This minute counter counts from "00" to "01," "02," and up to 59 minutes, after which it starts again from

00 minutes.

3) Hour counter

Address

Function

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

2

HOUR

!

!

20

10

8

4

2

1

• This hour counter counts from "00" hours to "01," "02," and up to 23 hours, after which it starts again from

00 hours.

8.2.7. Day counter (Reg - 3)

Address

Function

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

3

WEEK

!

6

5

4

3

2

1

0

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

•The day (of the week) is indicated by 7 bits, bit 0 to bit 6.

The day data values are counted as: Day 01h → Day 02h → Day 04h → Day 08h → Day 10h → Day 20h → Day 40h → Day 01h → Day 02h, etc.

•The correspondence between days and count values is shown below.

WEEK	bit 7	bit 6	bit 5	bit 4	bit 3	bit 2	bit 1	bit 0	Day	Data [h]

	0	0	0	0	0	0	0	1	Sunday	01 h
	0	0	0	0	0	0	1	0	Monday	02 h
Write/Read	0	0	0	0	0	1	0	0	Tuesday	04 h
Write/Read	0	0	0	0	1	0	0	0	Wednesday	08 h
	0	0	0	1	0	0	0	0	Thursday	10 h
	0	0	1	0	0	0	0	0	Friday	20 h
	0	1	0	0	0	0	0	0	Saturday	40 h
	∗ Do not set "1" to more than one day at the same time.
Write prohibit	Also, note with caution that any setting other than the								−	−
Write prohibit	seven shown above should not be made as it may								−	−
	seven shown above should not be made as it may
	interfere with normal operation.

Page - 11

MQ372-02

Contents

Page In pursuit of "Saving" Technology ,Epson electronic device "Saving Epson IS energy savings •The material is subject to change without notice 7.1. DC characteristics Page MQ372-02 RX - 8581 SA RX - 8581 JE RX - 8581 NB Signal I/O Item Symbol Condition Rating Unit SCL SDA 8.1. Overview of Functions 1) Clock functions 2)Fixed-cycleinterrupt generation function 3)Time update interrupt function 4)Alarm interrupt function 5)32.768-kHzclock output Address 8.2.2. Control register (Reg F) STOP RESET 1) UIE (Update Interrupt Enable) bit When a time update interrupt event occurs, an interrupt signal is not 4) STOP bit Writing a "0" to this bit cancels stop status (restarts operations) STOP Description [Normal operation mode] 8.2.3. Flag register (Reg-E) Flag register ∗ 1) ∗ 2) 1)UF (Update Flag) bit 8.2.4. Extension register (Reg-D) WADA USEL TSEL1 ∗ 3) Page Page 8.3. Fixed-cycleTimer Interrupt Function 8.3.1. Diagram of fixed-cycletimer interrupt function TE bit TIE bit /INT output 8.3.2. Related registers for function of time update interrupts TSEL1 TSEL0 interrupts from occurring inadvertently while entering settings When the SCL pin SDA pin /INT pin 8.4.1. Time update interrupt function diagram (2)When a time update interrupt event occurs, the UF bit value becomes "1 When the UF bit value is "1" its value is retained until it is cleared to zero (4)When a time update interrupt occurs, /INT pin output is low if UIE = "1 If UIE = "0" when a timer update interrupt occurs, the /INT pin status remains 8.4.2. Related registers for time update interrupt functions 1)USEL (Update Interrupt Select) bit Selects "second update" (once per second) as the timing for generation of interrupt events Selects "minute update" (once per minute) as the timing for generation of Page 8.5.2. Related registers from occurring inadvertently while entering settings 1) WADA (Week Alarm /Day Alarm) bit WADA Sets WEEK as target of alarm function 3) AF (Alarm Flag) bit The AF bit is cleared to zero to prepare for the next status detection Alarm interrupt events are not detected Alarm interrupt events are detected 4) AIE (Alarm Interrupt Enable) bit 8.6. Reading/Writing Data via the I2C Bus Interface 8.6.3. Starting and stopping I2C bus communications 0.95 s ( Max. ) 1) START condition, repeated START condition, and STOP condition (1)START condition The SDA level changes from high to low while SCL is at high level 8.6.4.Data transfers and acknowledge responses during I2C-BUScommunications 1)Data transfers However, the transfer time must be no longer than 0.95 seconds After address Fh, incrementation goes to address 0h 2)Data acknowledge response (ACK signal) Page Page RX-8581SA (SOP - 14 pin) •External dimensions R8581 E 1234A •Recommended soldering Page (1) Static electricity (2) Noise (3)Voltage levels of input pins (4) Handling of unused pins 11.2.Notes on packaging Distributor AMERICA EPSON ELECTRONICS AMERICA, INC HEADQUARTER 150 River Oaks Parkway, San Jose, CA 95134, U.S.A