2 ctbr: timebase counter clear register – FUJITSU MB91460 SERIES FR60 User Manual

Page 282

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Chapter 19 Timebase Timer

4.Register

• Bit1: Enabling the synchronous reset operation

• Ordinary operation reset: Immediately resets the operation initialization when the operation initialization

reset (RST) request is generated.
Synchronous reset: Resets the operation initialization after all accesses to the bus have stopped.

• Bit0: Synchronous standby operation enable

4.2 CTBR: Timebase Counter Clear Register

This register is used to initialize the timebase counter.

• CTBR: Address 0483h (Access: Byte)

(Refer to “

Meaning of Bit Attribute Symbols (Page No.10)

” for the attributes)

• Continuously writing

“

A5

H

”

,

“

5A

H

”

in the timebase counter clear register clears the timebase counter

immediately after writing

“

5A

H

”

. (All bits are

“

0

”

)

There is no time restrictions between

“

A5

H

”

and

“

5A

H

”

, but if

“

A5

H

”

is written followed by the one other than

“

5A

H

”

, you should write

“

A5

H

”

again. If not, the timebase counter cannot be cleared even if

“

5A

H

”

is written.

• The read value is indefinite.

• Clearing the timebase counter using the timebase counter clear register temporarily modifies the relevant

items shown below.

• Oscillation stability wait interval

• Watchdog timer period

• Timebase timer period

SYNCR

Operation

0

Ordinary reset operation

1

Synchronous reset operation enable

SYNCS

Operation

0

Ordinary reset operation (In this product, any setting is prohibited)

1

Synchronous standby operation enable (Be sure to set before making the transition to standby)

7

6

5

4

3

2

1

0

bit

D7

D6

D5

D4

D3

D2

D1

D0

X

X

X

X

X

X

X

X

Initial value

RX/W

RX/W

RX/W

RX/W

RX/W

RX/W

RX/W

RX/W

Attribute

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