XC68HC705F32 Motorola, XC68HC705F32 Datasheet - Page 42

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

3
EEPGM — EEPROM programming power enable
EEPGM must be set to enable the EEPGM function. When set, EEPGM turns on the charge pump
and enables the programming (or erasing) power to the EEPROM array. When clear, this power is
switched off. This will enable pulsing of the programming voltage to be controlled internally. This
bit can be read at any time, but can only be written to if LATCH = 1, i.e. if LATCH is not set, then
EEPGM cannot be set. Reset clears this bit.
3.5.2
To program a byte of EEPROM, set LATCH = CPEN = 1, set ER1 = ER0 = 0, write data to the
desired address and then set EEPGM for a time t
There are three possibilities for erasing data from the EEPROM array, depending on how much
data is affected.
•
•
•
To terminate the programming or erase sequence, clear EEPGM, wait for a time t
programming voltage to fall, and then clear LATCH and CPEN to release the buses. Following
each erase or programming sequence, clear all programming control bits.
3.5.3
The following program is an example of the EEPROM programming sequence, using the timer to
implement the required delay and assuming a 1 MHz bus frequency.
MOTOROLA
3-8
To erase a byte of EEPROM, set LATCH = CPEN = 1, set ER1 = 0 and ER0 = 1, write data to
the desired address and then set EEPGM for a time t
To erase a block of EEPROM, set LATCH = CPEN = 1, set ER1 = 1 and ER0 = 0, write data
to any address in the block and then set EEPGM for a time t
To bulk erase the EEPROM, set LATCH = CPEN = 1, set ER1 = ER0 = 1, write data to any
address in the array and then set EEPGM for a time t
1 (set)
0 (clear) –
Programming and erasing procedures
Sample EEPROM programming sequence
–
Programming power connected to the EEPROM array.
Programming power switched off.
MEMORY AND REGISTERS
EPGM
.
EBYTE
EBULK
.
.
EBLOCK
.
FPV
MC68HC05F32
to allow the