mc9s12uf32 Freescale Semiconductor, Inc, mc9s12uf32 Datasheet - Page 109

• Manufacturer Part Number: mc9s12uf32
• Description: System Chip Guide V01.05
• Manufacturer: Freescale Semiconductor, Inc

A.2 NVM, Flash
A.2.1 NVM timing
The time base for all NVM program or erase operations is derived from the oscillator. A minimum
oscillator frequency f
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. Attempting to program or erase the NVM modules at
a lower frequency a full program or erase transition is not assured.
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 f
The minimum program and erase times shown in Table A-9 are calculated for maximum f
maximum f
A.2.1.1 Single Word Programming
The programming time for single word programming is dependant on the bus frequency as a well as on
the frequency f
A.2.1.2 Burst Programming
This applies only to the Flash 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:
The time to program a whole row is:
Burst programming is more than 2 times faster than single word programming.
A.2.1.3 Sector Erase
Erasing a 512 byte Flash sector takes:
Freescale Semiconductor
NOTE:
bus
. The maximum times are calculated for minimum f
Unless otherwise noted the abbreviation NVM (Non Volatile Memory) is used for
Flash.
NVMOP
NVMOSC
and can be calculated according to the following formula.
is required for performing program or erase operations. The NVM modules
t
t
swpgm
t
bwpgm
brpgm
=
=
=
9
t
4
swpgm
---------------------
f
NVMOP
---------------------
f
NVMOP
System on a Chip Guide — 9S12UF32DGV1/D V01.05
1
1
+
31 t
+
+
25
9
bwpgm
NVMOP
----------
f
----------
f
bus
bus
1
1
and a f
bus
of 2MHz.
NVMOP
NVMOP
.
and
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