EM78P156EL
OTP ROM
Word 0
Bit12~Bit0
Word 1
Bit12~Bit0
1. Code Option Register (Word 0)
Bit12
Bit11
Bit10 Bit9
MS /ENWDT CLK
CS
WORD 0
Bit8 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
HLF - HLP -
-
-
-
-
-
• Bit 12 (MS):Oscillator type selection.
0: RC type
1: XTAL type (XTAL1 and XTAL2)
• Bit 11 (/ENWDT): Watchdog timer enable bit.
0: Enable
1: Disable
• Bit 10 (CLK): Instruction period option bit.
0: two oscillator periods.
1: four oscillator periods.
Refer to the section on Instruction Set.
• Bit 9 (CS): Code Security Bit
0: Security On
1: Security Off
• Bit 8 (HLF): XTAL frequency selection
0: XTAL2 type (low frequency, 32.768KHz)
1: XTAL1 type (high frequency)
This bit will affect system oscillation only when Bit12 (MS) is “1”. When MS is”0”, HLF must be “0”.
<Note>: The transient point of system frequency between HXT and LXY is around 400 KHz.
• Bit 7: Reserved.
The bit set to “1” all the time.
• Bit 6 (HLP): Power selection.
0: Low power
1: High power
• Bit 5~0 : Customer’s ID code
2. Customer ID Register (Word 1)
Bit 12~Bit 0
XXXXXXXXXXXXX
• Bit 12~0: Customer’s ID code
This specification is subject to change without prior notice.
30
07.29.2004 (V1.3)