MC9S08AW60 Datasheet, PDF (50/320 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 4 Memory
4.4.1 Features
Features of the FLASH memory include:
• FLASH Size
— MC9S08AW60 — 63280 bytes (124 pages of 512 bytes each)
— MC9S08AW48 — 49152 bytes (96 pages of 512 bytes each)
— MC9S08AW32 — 32768 bytes (64 pages of 512 bytes each)
• Single power supply program and erase
• Command interface for fast program and erase operation
• Up to 100,000 program/erase cycles at typical voltage and temperature
• Flexible block protection
• Security feature for FLASH and RAM
• Auto power-down for low-frequency read accesses
4.4.2 Program and Erase Times
Before any program or erase command can be accepted, the FLASH clock divider register (FCDIV) must
be written to set the internal clock for the FLASH module to a frequency (f_FCLK) between 150 kHz and
200 kHz (see Section 4.6.1, “FLASH Clock Divider Register (FCDIV)”). This register can be written only
once, so normally this write is done during reset initialization. FCDIV cannot be written if the access error
flag, FACCERR in FSTAT, is set. The user must ensure that FACCERR is not set before writing to the
FCDIV register. One period of the resulting clock (1/f_FCLK) is used by the command processor to time
program and erase pulses. An integer number of these timing pulses are used by the command processor
to complete a program or erase command.
Table 4-5 shows program and erase times. The bus clock frequency and FCDIV determine the frequency
of FCLK (f_FCLK). The time for one cycle of FCLK is t_FCLK = 1/f_FCLK. The times are shown as a number
of cycles of FCLK and as an absolute time for the case where t_FCLK = 5 µs. Program and erase times
shown include overhead for the command state machine and enabling and disabling of program and erase
voltages.
Table 4-5. Program and Erase Times
Parameter
Cycles of FCLK
Time if FCLK = 200 kHz
Byte program
9
45 µs
Byte program (burst)
4
20 µs¹
Page erase
4000
20 ms²
Mass erase
20,000
100 ms²
1 _{Excluding start/end overhead}
2 _{Because the page and mass erase times can be longer than the COP watchdog timeout, the}
COP should be serviced during any software erase routine.
MC9S08AW60 Data Sheet, Rev.1.0
50
Freescale Semiconductor