EM78P221/2N
8-Bit Microcontroller with OTP ROM
48
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Product Specification (V1.0) 10.19.2007
(This specification is subject to change without further notice)
Bits 12 ~ 11 (Type 1, Type 0):
Type selection for EM78P221N or EM78P222N
Type 1, Type 0
MCU Type
00
Not for use
01
Not for use
10
EM78P221N (24 pins)
11
EM78P222N (28 pins)
Note:
LVR1 and LVR0 are at Bank 3-R7, when using ICE.
Bits 10 ~ 9 (LVR1 ~ LVR0):
Low Voltage Reset control bits
LVR1, LVR0
VDD Reset Level
VDD Release Level
11
NA (Power-on Reset) (Default)
10 2.5V 2.7V
01 3.0V 3.2V
00 4.0V 4.2V
Bit 8 (CLKS):
Instruction time period option bit
0
= two oscillator time periods
1
= four oscillator time periods
(Default)
Refer to Section 6.12 for Instruction Set
Bit 7 (ENWDTB):
Watchdog timer enable bit
0
= Enable
1
= Disable (default)
Bits 6, 5 & 4 (OSC2, OSC1 & OSC0):
Oscillator Mode Selection bits
Oscillator Modes
OSC2
OSC1
OSC0
ERC
1
(External RC oscillator mode); P52/OSCO act as P52
0
0
0
ERC
1
(External RC oscillator mode); P52/OSCO act as OSCO
0
0
1
IRC
2
(Internal RC oscillator mode); P52/OSCO act as P52
0
1
0
IRC
2
(Internal RC oscillator mode); P52/OSCO act as OSCO
0
1
1
LXT1
3
(Frequency range of XT mode is 1MHz~100kHz)
1
0
0
HXT1
3
(Frequency range of XT mode is 16MHz~6MHz)
1
0
1
LXT2
3
(Frequency range of XT mode is 32kHz)
1
1
0
HXT2
3
(Frequency range of XT mode is 6MHz~1MHz) (Default)
1
1
1
1
In ERC mode, OSCI is used as oscillator pin. OSCO/P52 is defined by code option Word 0 Bit 6 ~ Bit 4.
2
In IRC mode, P53 is normal I/O pin. OSCO/P52 is defined by code option Word 0 Bit 6 ~ Bit 4.
3
In LXT1, LXT2, HXT1 and HXT2 modes; OSCI and OSCO are used as oscillator pins. These pins cannot
and should not be defined as normal I/O pins.
Bit 3:
Not used (Reserved). This bit is set to 0 all the time
Bits 2 ~ 0 (PR2 ~ PR0):
Protect Bits
PR2 ~ PR0 are protect bits. Each protect status is as follows:
PR2
PR1
PR0
Protect
0 0 0
Enable
1 1 1 Disable
(Default)