EM78P156N

OTP ROM

 

VCC

 

 

 

 

 

D

P

Q

 

IRQn

 

R

 

/IRQn

CLK

 

_

 

INT

 

 

C

Q

RFRD

IRQm

 

 

L

 

 

 

RF

 

 

 

 

ENI/DISI

 

Q

P

D

IOD

 

R

 

_

C

CLK

IOCFWR

 

Q

 

IOCF

L

 

 

 

 

 

/RESET

IOCFRD

RFWR

Fig. 10 Interrupt Input Circuit4.7Oscillator1.Oscillator Modes

The EM78P156N can be operated in three different oscillator modes, such as External RC oscillator mode (ERC), High XTAL oscillator mode (HXT), and Low XTAL oscillator mode (LXT). User can select one of them by programming OSC and HLF in the CODE option register. Table 6 depicts how these three modes are defined.

The up-most limited operation frequency of crystal/resonator on the different VDDs is listed in Table 7.

Table 8 Oscillator Modes Defined by OSC and HLP

Mode

OSC

HLF

HLP

 

 

 

 

ERC(External RC oscillator mode)

0

*X

*X

HXT(High XTAL oscillator mode)

1

1

*X

LXT(Low XTAL oscillator mode)

1

0

0

<Note> 1. X, Don’t care

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

This specification is subject to change without prior notice. 26

07.29.2004 (V1.2)