IBM EM78P447N manual Bit 8 CLKS Instruction period option bit 0 two oscillator periods

Models: EM78P447N

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Bit 8 (CLKS): Instruction period option bit.

EM78P447N

8-Bit Microcontroller with OTP ROM

Bit 8 (CLKS): Instruction period option bit.

0:two oscillator periods.

1:four oscillator periods.

Refer to the section on Instruction Set.

Bit 7(ENWDTB): Watchdog timer enable bit.

0:Enable

1:Disable

Bit 6: Type selection for EM78P447NA or EM78P447NB

0:EM78P447NB

1:EM78P447NA

Bit 5 (HLF): XTAL frequency selection

0:XTAL2 type (low frequency, 32.768KHz)

1:XTAL1 type (high frequency)

This bit will affect system oscillation only when Bit4 (OSC) is “1”. When OSC is”0”, HLF must be “0”.

NOTE

The transient point of system frequency between HXT and LXY is around 400 KHz.

Bit 4 (OSC): Oscillator type selection.

0:RC type

1:XTAL type (XTAL1 and XTAL2) Bit 3 (HLP): Power selection.

0:Low power

1:High power

Bit 2~0 (PR2~PR0): Protect Bit

PR2~PR0 are protect bits, protect type as following

 

PR2

 

 

PR1

 

PR0

 

Protect

 

 

 

0

 

 

0

 

0

 

Enable

 

 

0

 

 

0

 

1

 

Enable

 

 

0

 

 

1

 

0

 

Enable

 

 

0

 

 

1

 

1

 

Enable

 

 

1

 

 

0

 

0

 

Enable

 

 

1

 

 

0

 

1

 

Enable

 

 

1

 

 

1

 

0

 

Enable

 

 

1

 

 

1

 

1

 

Disable

 

 

 

 

 

 

 

 

 

 

 

 

Product Specification (V1.1) 03.30.2005

 

 

 

 

27

(This specification is subject to change without further notice)

Page 31
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IBM EM78P447N manual Bit 8 CLKS Instruction period option bit 0 two oscillator periods