Chapter 4 Memory
MC9S08QL8 MCU Series Reference Manual, Rev. 1
44
NXP Semiconductors
4.5
Flash
The flash memory is primarily for program storage. In-circuit programming allows the operating program
to be loaded into the flash memory after final assembly of the application product. It is possible to program
the entire array through the single-wire background debug interface. Because no special voltages are
needed for flash erase and programming operations, in-application programming is also possible through
other software-controlled communication paths. For a more detailed discussion of in-circuit and
in-application programming, refer to the
HCS08 Family Reference Manual, Volume I,
NXP
Semiconductors document order number HCS08RMv1.
4.5.1
Features
Features of the flash memory include:
•
Flash size
— MC9S08QL8: 8,192 bytes (16 pages of 512 bytes each)
— MC9S08QL4: 4,096 bytes (8 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
4.5.2
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
Section 4.7.1, 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 is used by the command processor to complete
a program or erase command.
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
s. Program and erase times
shown include overhead for the command state machine and enabling and disabling of program and erase
voltages.
Summary of Contents for MC9S08QL4
Page 4: ...MC9S08QL8 MCU Series Reference Manual Rev 1 4 NXP Semiconductors...
Page 36: ...Chapter 3 Modes of Operation MC9S08QL8 MCU Series Reference Manual Rev 1 36 NXP Semiconductors...
Page 56: ...Chapter 4 Memory MC9S08QL8 MCU Series Reference Manual Rev 1 56 NXP Semiconductors...
Page 172: ...Modulo Timer S08MTIMV1 MC9S08QL8 MCU Series Reference Manual Rev 1 172 NXP Semiconductors...
Page 238: ...Development Support MC9S08QL8 MCU Series Reference Manual Rev 1 238 NXP Semiconductors...
Page 239: ......
