User's Guide

Preface ....................................................................................................................................... 5

1 Introduction to the Timer ...................................................................................................... 6

2 Timer Modes ....................................................................................................................... 8

2.1 64-Bit Timer Mode ....................................................................................................... 8

2.2 Dual 32-Bit Timer Modes ............................................................................................... 8

2.3 Counter and Period Registers Used in GP Timer Modes ........................................................ 12

3 Timer Operation ................................................................................................................ 13

3.1 Timer Mode Selection ................................................................................................. 13

3.2 Timer Enabling ......................................................................................................... 13

3.3 Timer Clock Source Selection ........................................................................................ 14

3.4 Timer Output Mode Selection ........................................................................................ 14

3.5 Timer Counting ......................................................................................................... 15

3.6 Timer Reset Sources .................................................................................................. 15

3.7 Timer Interrupt Rate ................................................................................................... 15

3.8 Timer Emulation Modes ............................................................................................... 16

3.9 Timer Operation Boundary Conditions .............................................................................. 16

3.10 Initializing the Timer ................................................................................................... 18

4 Watchdog Timer Mode ....................................................................................................... 19

4.1 Timer Output Signal and Timer Interrupt Signal in Watchdog Mode ............................................ 19

4.2 Watchdog Timer Mode Restrictions ................................................................................. 19

4.3 Watchdog Timer Mode Operation ................................................................................... 19

4.4 Watchdog Timer Register Write Protection ......................................................................... 22

5 Timer Registers ................................................................................................................. 23

5.1 Emulation Management and Clock Speed Register (EMUMGT_CLKSPD) .................................... 24

5.2 Timer Counter Registers (CNTHI and CNTLO) .................................................................... 25

5.3 Timer Period Registers (PRDHI and PRDLO) ..................................................................... 26

5.4 Timer Control Register (TCR) ........................................................................................ 27

5.5 Timer Global Control Register (TGCR) ............................................................................. 30

5.6 Watchdog Timer Control Register (WDTCR) ....................................................................... 31

Appendix A Revision History ...................................................................................................... 32

SPRU818B–December 2005–Revised September 2010 Table of Contents

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