Freescale Semiconductor Block Guide, EETX4K Figure 4-1 Determination Procedure for PRDIV8 and EDIV Bits, ,

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Block Guide — S12EETX4KV0 V00.04

Figure 4-1 Determination Procedure for PRDIV8 and EDIV Bits

PRDIV8=1

yes

PRDIV8=0 (reset)

12.8MHz?

EECLK=(PRDCLK)/(1+EDIV[5:0])

PRDCLK=oscillator_clock

PRDCLK=oscillator_clock/8

PRDCLK[MHz]*(5+Tbus[µs]) no

EDIV[5:0]=PRDCLK[MHz]*(5+Tbus[µs])-1

yes

START

Tbus< 1µs?

an integer?

EDIV[5:0]=INT(PRDCLK[MHz]*(5+Tbus[µs]))

1/EECLK[MHz] + Tbus[µs]> 5

AND

EECLK> 0.15MHz

END

yes

EDIV[5:0]> 4?

ALL COMMANDS IMPOSSIBLE

yes

ALL COMMANDS IMPOSSIBLE

TRY TO DECREASE Tbus

yes

oscillator_clock

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Contents

Main EETX4K Block Guide V00.04 Page Table of Contents Section 1 Introduction Section 2 External Signal Description Section 3 Memory Map and Registers Section 4 Functional Description Page List of Figures Page List of Tables Page Page Page Section 1 Introduction 1.1 Overview 1.1.1 Glossary Command Write Sequence 1.2 Features EETX4K Page Section 3 Memory Map and Registers 3.1 Overview 3.2 Module Memory Map Figure 3-1 EEPROM Memory Map Page 3.3 Register Descriptions 3.3.1 ECLKDIV EEPROM Clock Divider Register 3.3.2 RESERVED1 3.3.3 RESERVED2 3.3.4 ECNFG EEPROM Configuration Register 3.3.5 EPROT EEPROM Protection Register 3.3.6 ESTAT EEPROM Status Register 3.3.7 ECMD EEPROM Command Register 3.3.8 RESERVED3 3.3.9 EADDR EEPROM Address Registers 3.3.10 EDATA EEPROM Data Registers Page Section 4 Functional Description 4.1 EEPROM Command Operations 4.1.1 Writing the ECLKDIV Register Page Figure 4-1 Determination Procedure for PRDIV8 and EDIV Bits 4.1.2 Command Write Sequence 4.1.3 EEPROM Commands Page Page Page Page Figure 4-7 Example Sector Modify Command Flow 4.1.4 Illegal EEPROM Operations Page 4.2 Wait Mode 4.3 Stop Mode 4.4 Background Debug Mode 4.5 EEPROM Module Security 4.5.1 Unsecuring the MCU in Special Single Chip Mode via the BDM 4.6 Resets 4.6.1 EEPROM Reset Sequence 4.6.2 Reset While EEPROM Command Active 4.7 Interrupts 4.7.1 Description of EEPROM Interrupt Operation Page Index