XC68HC705F32 Motorola, XC68HC705F32 Datasheet - Page 40

• Manufacturer Part Number: XC68HC705F32
• Description: MICROCONTROLLER
• Manufacturer: Motorola

3
3.4
The MC68HC05F32 has 224 bytes of bootloader ROM plus 16 bytes of bootloader vectors, from
$FF00 to $FFEF. These are included primarily for factory test purposes.
3.5
256 bytes of user EEPROM reside at addresses $0400 to $04FF.
Programming or erasing the EEPROM can be done by the user on a single byte basis; erasing
may also be performed on a block or bulk basis. All programming or erasing is accomplished by
manipulating the programming register (EEPROG), located at address $001C.
Note:
Caution: There is a restriction on the use of indexed addressing for EEPROM read operations.
3.5.1
CPEN — Charge pump enable
When set, CPEN enables the charge pump which produces the internal programming voltage.
This bit should be set at the same time as the LATCH bit. The programming voltage will not be
available until EEPGM is set. The charge pump should be disabled when not in use. CPEN is
readable and writable and is cleared by reset.
MOTOROLA
3-6
EEPROM programming (EEPROG) $001C
1 (set)
0 (clear) –
The erased state of an EEPROM byte is ‘$FF’. This means that a write forces zeros to
the bits specified, whilst bits defined as ones are unchanged by a write operation.
When the base address of an indexed read of an EEPROM location is within the
EEPROM address range ($0400 to $04FF), the read may not be successful.
e.g. LDA (BASE ADDRESS), X – may not give the correct result when the base
address is in the range $0400 to $04FF. However if the base address is outwith the
EEPROM address range, the read operation will be successful. This restriction applies
to all operations capable of using indexed addressing.
Bootloader ROM
EEPROM
EEPROM programming register
–
Charge pump enabled.
Charge pump disabled.
Address
MEMORY AND REGISTERS
0
bit 7
CPEN
bit 6
0
bit 5
ER1
bit 4
ER0 LATCH EERC EEPGM 0000 0000
bit 3
bit 2
bit 1
MC68HC05F32
bit 0
on reset
State