MC9S12GRMV1 Datasheet, PDF (801/1292 Pages) Freescale Semiconductor, Inc – MC9S12G Family Reference Manual and Data Sheet

24.4 Functional Description
16 KByte Flash Module (S12FTMRG16K1V1)
24.4.1 Modes of Operation
The FTMRG16K1 module provides the modes of operation normal and special . The operating mode is
determined by module-level inputs and affects the FCLKDIV, FCNFG, and EEPROT registers (see
Table 24-25).
24.4.2 IFR Version ID Word
The version ID word is stored in the IFR at address 0x0_40B6. The contents of the word are defined in
Table 24-24.
Table 24-24. IFR Version ID Fields
[15:4]
Reserved
[3:0]
VERNUM
• VERNUM: Version number. The first version is number 0b_0001 with both 0b_0000 and 0b_1111
meaning ‘none’.
24.4.3 Internal NVM resource (NVMRES)
IFR is an internal NVM resource readable by CPU , when NVMRES is active. The IFR fields are shown
in Table 24-5.
The NVMRES global address map is shown in Table 24-6.
24.4.4 Flash Command Operations
Flash command operations are used to modify Flash memory contents.
The next sections describe:
• How to write the FCLKDIV register that is used to generate a time base (FCLK) derived from
BUSCLK for Flash program and erase command operations
• The command write sequence used to set Flash command parameters and launch execution
• Valid Flash commands available for execution, according to MCU functional mode and MCU
security state.
24.4.4.1 Writing the FCLKDIV Register
Prior to issuing any Flash program or erase command after a reset, the user is required to write the
FCLKDIV register to divide BUSCLK down to a target FCLK of 1 MHz. Table 24-8 shows recommended
values for the FDIV field based on BUSCLK frequency.
MC9S12G Family Reference Manual, Rev.1.23
Freescale Semiconductor
803