mc68hc05bs8 Freescale Semiconductor, Inc, mc68hc05bs8 Datasheet - Page 28

• Manufacturer Part Number: mc68hc05bs8
• Description: Mc68hc05 Family Of Low-cost Single-chip Microcontrollers.
• Manufacturer: Freescale Semiconductor, Inc

4
4.5
The EEPROM consists of 512 bytes, from $0200 to $03FF. A charge pump is built on the chip for
the operation of EEPROM. Programming and erasing are controlled by writing to the EEPROM
Control register at address $0007.
4.5.1
EEOSC - EEPROM Charge Pump Oscillator Enable
EER1, EER0 - EEPROM Erase Mode Select Bits
The EEPROM memory space is divided into two 256 byte blocks. Block 1 is located at address
$0200-$02FF, and block 2 is located at $0300-$03FF. Providing the EELAT and EEPGM bits are
“1”, the EER1 and EER0 bits indicate whether the access to the EEPROM is for an erase or
programming purpose. Block protect function applies on block 2 of the EEPROM memory space.
EELAT - EEPROM Programming Latch Control
4-2
1 (set)
0 (clear) –
These two bits select one of the three erase modes. Refer to Table 4-1 below.
1 (set)
0 (clear) –
EEPCR
EEPROM
EEPROM Control Register
–
–
Internal oscillator turned on to clock the EEPROM charge pump.
It requires a time t
Internal oscillator turned off. EEPROM charge pump clocked by
internal bus clock.
EEPROM address and data bus configured for programming (writes
to EEPROM cause address and data to be latched). EEPROM is in
programming mode and cannot be read when this bit is set.
EEPROM address and data bus configured for normal reads. EER1,
EER0, and EEPGM are forced to “0”s.
EER1
Address bit 7
0
0
1
1
$0007
Table 4-1 Erase Mode Select
MEMORY AND REGISTERS
EER0
0
1
0
1
RCON
No erase
Byte erase
Block erase (block 1 or block 2)
Bulk erase (block 1 and block 2)
bit 6
to stabilize. (Min. 1 s).
ERASE MODE
bit 5
EEOSC EER1 EER0 EELAT EEPGM 0000 0000
bit 4
bit 3
bit 2
bit 1
MC68HC05BS8
bit 0
on reset
State
TPG