EM78P221/2N
8-Bit Microcontroller with OTP ROM
48 •
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)
