NXP Semiconductors freescale semiconductor MC13211, Reference Manual

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MCU Memory
MC1321x Reference Manual, Rev. 1.6
Freescale Semiconductor 11-9
11.4 FLASH
The FLASH memory is intended 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,
Freescale Semiconductor document order number HCS08RMv1.
11.4.1 Features
Features of the FLASH memory include:
• FLASH Size
— MC13211 — 16384 bytes (32 pages of 512 bytes each)
— MC13212 — 32768 bytes (64 pages of 512 bytes each)
— MC13213 — a high block of 59348 bytes (115 pages of 512 bytes each plus 1 page of 468
bytes) and a low block of 1920 bytes. The high block can be protected and the low block left
unprotected for use as non-volatile parameters.
• 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
11.4.2 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 11.6.1, “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 is used by the command processor to
complete a program or erase command.
Table 11-5 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
μ
s. Program and erase times
shown include overhead for the command state machine and enabling and disabling of program and erase
voltages.