MC68HC705B16CFN Freescale Semiconductor, MC68HC705B16CFN Datasheet - Page 48
Manufacturer Part Number
IC MCU 2.1MHZ 15K OTP 52-PLCC
Specifications of MC68HC705B16CFN
Number Of I /o
Program Memory Size
15KB (15K x 8)
Program Memory Type
256 x 8
352 x 8
Voltage - Supply (vcc/vdd)
4.5 V ~ 5.5 V
-40°C ~ 85°C
Package / Case
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
(1) This register is implemented in EEPROM; therefore reset has no effect on the individual bits.
To program a byte of EEPROM, the following steps should be taken:
While a programming operation is being performed, any access of the EEPROM array will not be
Warning: To program a byte correctly, it has to have been previously erased. It is advised that this
If a second word is to be programmed, it is important that the E1LAT bit be reset before restarting
the programming sequence otherwise any write to a new address will have no effect. This
condition provides a higher degree of security for the stored data.
User programs must be running from the RAM or ROM as the EEPROM will have its address and
data buses latched.
This register (OPTR), located at $0100, contains the secure and protect functions for the
EEPROM and allows the user to select options in a non-volatile manner. The contents of the
OPTR register are loaded into data latches with each power-on or external reset.
1 Set the E1LAT bit.
2 Write address/data to the EEPROM address to be programmed.
3 Set the E1PGM bit.
4 Wait for time t
5 Reset the E1LAT bit (to logic zero).
is done only for 0→1 transitions, as this saves excessive overwriting of EEPROM.
224 bytes of EEPROM (address $0120 to $01FF) can be program and erase protected
under the control of bit 1 of the OPTR register detailed in
EEPROM programming operation
Options register (OPTR)
MEMORY AND REGISTERS
SEC Not affected