Cirrus Logic EP73xx - Manual (Page 43)

EP7309/11/12 User’s Manual - DS508UM4 3-1
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Copyright Cirrus Logic, Inc. 2003
33
3
Chapter 3
3 Timers
Introduction
EP73xx has three general purpose timers that can serve as watchdogs for system
resources or and events. Two timers are based on the internal PLL or 13 MHz clock
and the third is fed by the RTC. Routines requiring periodic service to check status
and new values can make use of these timers.
Features
All timers have the following characteristics
• Programmable for two modes: free running and pre-scale
• Interrupt flags and corresponding mask for control and status
• Timer 16-bit read/write data register to set and read values. Can be
accessed at any time.
Timer Register List
Programming Example
;*****************************************************************************
; Enable TC1 Timer prescale = 2 kHz Program a 2 ms interrupt rate
;*****************************************************************************
;
TC1Prescale EQU 0x10 ; Set prescale in SYSCON1
TC1Timer EQU 0x14 ; Set 10 ms timer in TC1 timer
TC1Mask EQU 0x100 ; UnMask TC1 interrupt
ldr r12, =0x80000000 ; base address for Timers
ldr r1, =TC1Prescale
Table 3-1: Timer Registers
Address Name Type Size Description Page
0x8000.0300 TC1D R/W 16 TC1 Data Register page 3-3
0x8000.0340 TC2D R/W 16 TC2 Data Register page 3-3
0x8000.0380 RTCDR R/W 32 RTC Data Register page 3-3
0x8000.03C0 RTCMR R/W 32 RTC Match Register page 3-4