EM78P258N
8-Bit Microprocessor with OTP ROM
Bit 3 (HLP):
Power consumption selection
0 = Low power consumption, applies to working frequency
at or below 4MHz
1 = High power consumption, applies to working frequency
above 4MHz
Bit 2 ~ 0 (PR2 ~ PR0):
Protect Bits
PR2 ~ PR0 are protect bits. Each protect status is as
follows:
PR2
PR1
PR0
Protect
Enable
Enable
Enable
Enable
Enable
Enable
Enable
Disable
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
6.12.2 Code Option Register (Word 1)
WORD 1
Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
-
-
RCOUT NRHL NRE WDTPS CYES
C3
C2
C1
C0
RCM1 RCM0
Bits 12 ~ 11:
Not used (reserved). These bits are set to “1” all the time
Bit 10 (RCOUT): System clock output enable bit in IRC or ERC mode
0 = OSCO pin is open drain
1 = OSCO output system clock
Bit 9 (NRHL):
Noise rejection high/low pulses define bit. INT pin is falling edge
trigger
0 = Pulses equal to 8/fc [s] is regarded as signal
1 = Pulses equal to 32/fc [s] is regarded as signal (default)
NOTE
The noise rejection function is turned off under the LXT and sleep mode.
Bit 8 (NRE):
Noise rejection enable
0 = disable noise rejection
1 = enable noise rejection (default), but under Low XTAL oscillator
(LXT) mode, the noise rejection circuit is always disabled.
Product Specification (V1.0) 06.16.2005
• 63
(This specification is subject to change without further notice)
ELAN [ ELAN MICROELECTRONICS CORP ]
