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MC9S12NE64_06 Datasheet, PDF (532/554 Pages) Freescale Semiconductor, Inc – Microcontrollers
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Appendix A Electrical Characteristics
A.15 FLASH NVM Electrical Characteristics
A.15.1 NVM timing
The time base for all NVM program or erase operations is derived from the oscillator. A minimum
oscillator frequency fNVMOSC is required for performing program or erase operations. The NVM modules
do not have any means to monitor the frequency and will not prevent program or erase operation at
frequencies above or below the specified minimum. Programming or erasing the NVM modules at a lower
frequency will not result in a full program or erase transition.
The FLASH program and erase operations are timed using a clock derived from the oscillator using the
FCLKDIV register. The frequency of this clock must be set within the limits specified as fNVMOP.
The minimum program and erase times shown in Table A-25 are calculated for maximum fNVMOP and
maximum fbus. The maximum times are calculated for minimum fNVMOP and a fbus of 2 MHz.
A.15.1.1 Single Word Programming
The programming time for single word programming is dependent on the bus frequency as a well as on the
frequency f¨NVMOP and can be calculated according to the following formula.
tswpgm = 9 ⋅ f--N----V----1M-----O----P-- + 25 ⋅ -f-b--1--u---s-
A.15.1.2 Burst Programming
FLASH programming where up to 32 words in a row can be programmed consecutively using burst
programming by keeping the command pipeline filled. The time to program a consecutive word can be
calculated as:
tbwpgm = 4 ⋅ f--N----V----1M-----O----P-- + 9 ⋅ f--b--1--u---s-
The time to program a whole row is:
tbrpgm = tswpgm + 31 ⋅ tbwpgm
Burst programming is more than two times faster than single word programming.
A.15.1.3 Sector Erase
Erasing a 512 byte FLASH sector takes:
tera ≈ 4000 ⋅ f--N----V----1M-----O----P--
The setup times can be ignored for this operation.
MC9S12NE64 Data Sheet, Rev. 1.1
532
Freescale Semiconductor
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