XC908AS60ACFU Motorola Semiconductor Products, XC908AS60ACFU Datasheet - Page 555

• Manufacturer Part Number: XC908AS60ACFU
• Description: MC68HC908AZ60A, MC68HC908AS60A Hcmos Microcontroller Unit Technical Data
• Manufacturer: Motorola Semiconductor Products

29.2.2.6 FLASH Endurance
29.2.3 EEPROM
29.2.3.1 EEPROM Architecture
29.2.3.2 EEPROM Clock Source and Pre-scaler
MC68HC908AZ60A — Rev 2.0
MOTOROLA
A further significant change is that high voltage (V
on the IRQ pin to program or erase the FLASH block protect registers.
The FLASH endurance is now specified as 10,000 write / erase cycles
as opposed to less than 1000 before.
Like the FLASH, EEPROM-1 and EEPROM-2 are also made from a new
NVM technology. However, unlike the FLASH, the bit polarity remains
the same i.e. programmed=0, erased=1. The architecture and basic
programming and erase operations are unchanged.
The first major difference on the new EEPROM is that it requires a
constant time base source to ensure secure programming and erase
operations. This is done by firstly selecting which clock source is going
to drive the EEDIVG clock divider input using a new bit 7 introduced onto
the CONFIG-2 register $FE09. Next the divide ratio from this source has
to be set by programming an 11-bit time base pre-scalar into bits spread
over two new registers, EEDIVxH and EEDIVxL (where x=1 or 2 for
EEPROM-1 or EEPROM-2 arrays).
The EEDIVxH and EEDIVxL registers are volatile. However, they are
loaded upon reset by the contents of duplicate non-volatile
EEDIVxHNVR and EEDIVxLNVR registers much in the same way as the
array control registers (EEACRx) interact with the non-volatile registers
(EENVRx) for configuration control on the existing revision. As a result
of the new EEDIV clock described above bit 7 (EEBCLK) of the
EEPROM control registers (EECRx) is no longer used.
Changes from the MC68HC908AS60 and MC68HC908AZ60 (non-A suffix devices)
MC68HC908AS60 and MC68HC908AZ60
MC68HC908AS60 and MC68HC908AZ60
HI
) is no longer needed
Technical Data
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