MC9S12NE64CPVE Datasheet, PDF (88/554 Pages) Freescale Semiconductor, Inc – MC9S12NE64 Device Overview

Chapter 2 64 Kbyte Flash Module (S12FTS64KV3)
START
Tbus < 1µs?
NO
ALL COMMANDS IMPOSSIBLE
YES
PRDIV8=0 (reset)
OSCILLATOR
CLOCK
NO
> 12.8 MHZ?
YES
PRDIV8=1
PRDCLK=oscillator_clock/8
PRDCLK=oscillator_clock
PRDCLK[MHz]*(5+Tbus[µs]) ^NO
an integer?
YES
FDIV[5:0]=INT(PRDCLK[MHz]*(5+Tbus[µs]))
FDIV[5:0]=PRDCLK[MHz]*(5+Tbus[µs])-1
TRY TO DECREASE Tbus FCLK=(PRDCLK)/(1+FDIV[5:0])
1/FCLK[MHz] + Tbus[µs] > 5
AND
FCLK > 0.15 MHz
?
YES
END
NO
YES
FDIV[5:0] > 4?
NO
ALL COMMANDS IMPOSSIBLE
Figure 2-21. Determination Procedure for PRDIV8 and FDIV Bits
MC9S12NE64 Data Sheet, Rev. 1.1
88
Freescale Semiconductor