MC9S12E256 Datasheet, PDF (579/602 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

A.4.1.4 Mass Erase
Erasing a NVM block takes:
tm
ass
≈
20000
⋅
-----------1-------------
fNVMOP
The setup times can be ignored for this operation.
Appendix A Electrical Characteristics
A.4.1.5 Blank Check
The time it takes to perform a blank check on the Flash is dependant on the location of the first non-blank
word starting at relative address zero. It takes one bus cycle per word to verify plus a setup of the command.
t_check ≈ location ⋅ tcyc + 10 ⋅ tcyc
Table A-14. NVM Timing Characteristics
Conditions are shown in Table A-4 unless otherwise noted
Num C
Rating
Symbol
Min
Typ
Max
Unit
1 D External Oscillator Clock
f_NVMOSC
0.5
—
50¹
MHz
2
D Bus frequency for Programming or Erase Operations f_NVMBUS
1
—
—
MHz
3 D Operating Frequency
f_NVMOP
150
—
200
kHz
4
P Single Word Programming Time
t_swpgm
46²
—
74.5³
µs
5 D Flash Burst Programming consecutive word
t_bwpgm
20.4²
—
31³
µs
6 D Flash Burst Programming Time for 64 Word row
t_brpgm
1331.2² — 2027.5³
µs
7
P Sector Erase Time
t_era
20⁴
—
26.7³
ms
8
P Mass Erase Time
t_mass
100⁴
—
133³
ms
9 D Blank Check Time Flash per block
t _check
11⁵
—
65546⁶
7_tcyc
1 _{Restrictions for oscillator in crystal mode apply!}
2 _{Minimum Programming times are achieved under maximum NVM operating frequency fNVMOP and maximum bus frequency}
f_bus.
3 _{Maximum Erase and Programming times are achieved under particular combinations of fNVMOP and bus frequency f bus. Refer}
to formulae in Section A.4.1.1, “Single Word Programming” through Section A.4.1.4, “Mass Erase” for guidance.
4 _{Minimum Erase times are achieved under maximum NVM operating frequency fNVMOP.}
5 _{Minimum time, if first word in the array is not blank}
6 _{Maximum time to complete check on an erased block}
7 _{Where tcyc is the system bus clock period.}
MC9S12E256 Data Sheet, Rev. 1.08
Freescale Semiconductor
579