em78f644nso28s ELAN Microelectronics Corp, em78f644nso28s Datasheet - Page 97

• Manufacturer Part Number: em78f644nso28s
• Description: Flash Series 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

Product Specification (V1.0) 05.05.2010
(This specification is subject to change without further notice)
6.3.79 Bank1 R1C (Not Used)
6.3.80 Bank1 R1D: IRCS (IRC Frequency Selection Register)
Bits 7~6:
Bits 5~4 (RCM1 ~ RCM0): IRC Mode Frequency select bits
Bits 3~0: Not used, fixed to “0” all the time.
6.3.81 Bank1 R1E (Not Used)
6.3.82 Bank1 R1F: EEPROM CONTROL
Bit 7 (RD):
Bit 6 (WR):
Bit 5 (EEWE): EEPROM Write enable bit
Bit 7
Bit 7
RD
0
Bit 6
Bit 6
WR
Not used, fixed to “0” all the time.
WORD1 COBS0 = 0: The R1D<5,4> of the initialized values will keep
WORD1 COBS0 = 1: The R1D<5,4> of the initialized values will keep
0
RCM 1
Read control bit
0: Don’t execute EEPROM read
1: Read EEPROM contents (RD can be set by software. When Read
Write control bit
0: Write cycle to the EEPROM is completed.
1: Initiate a Write cycle (WR can be set by software. When Write
0: Prohibit Write to the EEPROM
1: Allow EEPROM Write cycles
0
0
1
1
instruction is completed, RD will be cleared by hardware.)
cycle is completed, WR will be cleared by hardware.)
EEWE
RCM1
Bit 5
Bit 5
RCM 0
0
1
0
1
EM78F648/644/642/641/548/544/542/541N
RCM0
EEDF
Bit 4
Bit 4
the same as WORD1<6,5>.
The R1D<5,4> can’t be changed.
the same as WORD1<6,5>.
The R1D<5,4> can be changed if you want to
work on other IRC frequency.
Ex: 4M
Frequency(MHz)
EEPC
Bit 3
Bit 3
16M
0
455kHz
16
4
8
Bit 2
Bit 2
0
0
8-Bit Microcontroller
Bit 1
Bit 1
0
0
Bit 0
Bit 0
0
0
• 87