em78p468n ELAN Microelectronics Corp, em78p468n Datasheet - Page 51

• Manufacturer Part Number: em78p468n
• Description: 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

Product Specification (V1.6) 12.31.2007
(This specification is subject to change without further notice)
6.11 Code Options
The EM78P468N/L has one Code Option word that is not a part of the normal program
memory. The option bits cannot be accessed during normal program execution.
Code Option Register and Customer ID Register arrangement distribution:
Word 1 of code options is for customer ID code application.
Word 0 of Code Options is for IC function setting. The following are the settings for
OTP IC programming:
Bits 12 ~ 10: Not used.
These bits are set to “1” all the time.
Bit 9 (CYES): Cycle select for JMP and CALL instructions
Bit 8 (HLFS): main or sub-oscillator select
Bit 7 (ENWDTB): Watchdog timer enable/disable bit.
Bit 6 (FSMD): sub-oscillator type selection.
Bits 5, 4 (FMMD1, 0): Main Oscillator Type Selection
Bits12~10
FSMD
0
0
0
1
1
1
1
CYES = “0”: only one instruction cycle (JMP or CALL) can be executed
CYES = “1”: two instructions cycles (JMP and CALL) can be executed
HLFS = “0”: CPU is set to select sub-oscillator when reset occurs.
HLFS = “1”: CPU is set to select main-oscillator when reset occurs.
ENWDTB = “0”: Enable watchdog timer.
ENWDTB = “1”: Disable watchdog timer.
Bit 12~Bit 0
Word 1
CYES HLFS ENWDTB
Bit 9
FMMD1
0
0
1
0
0
1
Bit 8
FMMD0
Bit 7
0
1
×
0
1
×
FSMD
Bit 6
Main Oscillator Type
Word 0
RC type
Crystal type
PLL type
RC type
Crystal type
PLL type
FMMD1 FMMD0
Bit 5
Bit 4
Bit 3
HLP
Sub Oscillator Type
8-Bit Microcontroller
Bit 2
PR2
RC type
RC type
RC type
Crystal type
Crystal type
Crystal type
EM78P468N/L
Bit 1
PR1
Bit 0
PR0
• 45