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Registers, 1 stcr: standby control register, Registers 4.1 stcr: standby control register – FUJITSU MB91460 SERIES FR60 User Manual

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Chapter 10 Standby

4.Registers

4. Registers

4.1 STCR: Standby Control Register

Used to control transition to the stop and sleep standby modes, and to specify the pin states and whether to
halt the oscillation during stop mode.

Note: See “

Chapter 9 Reset (Page No.139)

” also.

• STCR: Address 0481h (Access: Byte)

(See “

Meaning of Bit Attribute Symbols (Page No.10)

” for details of the attributes.)

• Bit7: Stop mode

• Goes to “0” when a reset (INIT pin input or software reset) occurs or on recovery from stop mode.

• Going directly from main PLL operation to stop mode is prohibited. (See “

8. Caution (Page No.165)

”.)

• Bit6: Sleep mode

• If this bit and the stop mode bit (STOP) bit are set to “1” at the same time, the device goes to stop mode.

• Goes to “0” when a reset (INIT pin input or software reset) occurs or on recovery from sleep mode.

• Bit5: High impedance mode

• The default setting is high impedance.

• Bit4: Software reset (SRST)

• Setting this bit to “0” invokes a software reset.

• Bit3-2: Oscillation stabilization time selection (OS[1:0])

• Setting these bits in the range “00”-“11” sets the oscillation stabilization time to use after recovering from

stop mode.
An INIT pin input reset or watchdog reset initialize this setting to its initial value.
(See “

Chapter 18 Timebase Counter (Page No.249)

”.)

• Bit1: Sub clock oscillation halt

7

6

5

4

3

2

1

0

bit

STOP

SLEEP

HIZ

SRST

OS1

OS0

OSCD2

OSCD1

0

0

1

1

0

0

1

1

Initial value

(INITX pin input)

0

0

1

1

X

X

1

1

Initial value

(Watchdog reset)

0

0

X

1

X

X

X

X

Initial value (Software reset)

R/W

R/W

R/W

R1, W

R/W

R/W

R/W

R/W

Attribute

STOP

Operation

0

Does not change to stop mode.

1

Changes to stop mode.

SLEEP

Operation

0

Does not change to sleep mode.

1

Changes to sleep mode.

HIZ

Operation

0

Maintain same pin states when changing to stop mode.

1

Set pin outputs to high impedance (Hi-z) during stop mode.

OSCD2

Operation of sub clock during stop mode

0

Continue oscillation

1

Halt oscillation