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3 wthr/wtmr/wtsr: hour/minute/second registers – FUJITSU MB91460 SERIES FR60 User Manual

Page 971

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955

Chapter 49 Real-Time Clock

4.Registers

4.3 WTHR/WTMR/WTSR: Hour/Minute/Second Registers

These registers hold time information (HH/MM/SS) for Real-time Clock.

• WTHR (Hour register): Address 04A8

H

(Access: Byte, Half-word)

• WTMR (Minute register): Address 04A9

H

(Access: Byte, Half-word)

• WTSR (Second register): Address 04AA

H

(Access: Byte, Half-word)

• The values written to the hour/minute/second registers are the initial values to be loaded to the hour/

minute/second counters.
By setting “1” to the update bit (WTCR.UPDT) or the start bit (WTCR.ST), the hour/minute/second
register values are written to the hour/minute/second counters.

• The hour/minute/second counter values are saved to the hour/minute/second registers every time when

the second counter overflows, that is, at intervals of one minute. When the hour/minute/second counters
are read, the saved count values, not written ones, are read.

• The hour/minute/second registers consist of two separate sets of registers: one for reading and the other

for writing.

(See “

8. Caution (Page No.961)

”.)

WTHR

7

6

5

4

3

2

1

0

bit

H4

H3

H2

H1

H0

X

X

X

X

X

Initial value

Unchanged Unchanged Unchanged Unchanged Unchanged

When reset

RX/WX

RX/WX

RX/WX

R,W

R,W

R,W

R,W

R,W

Attribute

WTMR

7

6

5

4

3

2

1

0

bit

M5

M4

M3

M2

M1

M0

X

X

X

X

X

X

Initial value

Unchanged Unchanged Unchanged Unchanged Unchanged Unchanged

When reset

RX/WX

RX/WX

R,W

R,W

R,W

R,W

R,W

R,W

Attribute

WTSR

7

6

5

4

3

2

1

0

bit

S5

S4

S3

S2

S1

S0

X

X

X

X

X

X

Initial value

Unchanged Unchanged Unchanged Unchanged Unchanged Unchanged

When reset

RX/WX

RX/WX

R,W

R,W

R,W

R,W

R,W

R,W

Attribute