Справочник Пользователя для IBM MiEM78P468N
EM78P468N/EM78P468L
8-Bit Microcontroller
Product Specification (V1.5) 02.15.2007
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(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 1
Bit 12~Bit 0
Word 0 of Code Options is for IC function setting. The following are the settings for
OTP IC programming:
Word 0
Bits12~10 Bit 9 Bit 8
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
1
CYES
HLFS ENWDTB FSMD
FMMD1 FMMD0
HLP PR2 PR1 PR0
Bits 12 ~ 10:
Not used.
These bits are set to “1” all the time.
Bit 9 (CYES):
Cycle select for JMP and CALL instructions
CYES = “0”:
only one instruction cycle (JMP or CALL) can be executed
CYES = “1”:
two instructions cycles (JMP and CALL) can be executed
Bit 8 (HLFS):
main or sub-oscillator select
HLFS = “0”:
CPU is set to select sub-oscillator when reset occurs.
HLFS = “1”:
CPU is set to select main-oscillator when reset occurs.
Bit 7 (ENWDTB):
Watchdog timer enable/disable bit.
ENWDTB = “0”:
Enable watchdog timer.
ENWDTB = “1”:
Disable watchdog timer.
Bit 6 (FSMD):
sub-oscillator type selection.
Bits 5, 4 (FMMD1, 0):
Main Oscillator Type Selection
FSMD
FMMD1
FMMD0
Main Oscillator Type
Sub Oscillator Type
0
0
0
RC type
RC type
0
0
1
Crystal type
RC type
0
1
×
PLL type
RC type
1
0
0
RC type
Crystal type
1
0
1
Crystal type
Crystal type
1
1
×
PLL type
Crystal type