Computer Hardware User's Guide

Timers
12-14
2) Configure the timer through the timer global-control register (with GO =
HLD = 0 ), the timer-counter register, and timer-period register, if necessary.
3) Start the timer by setting the GO/HLD bits of the timer global-control register.
Example 12–2 shows how to set up the ‘C3x timer to generate the maximum
clock frequency through the TCLKx pin.
Example 12–2. Maximum Frequency Timer Clock Setup
* Maximum Frequency Timer Clock Setup
*
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Timer0 .word 808020h ; Timer global control address
TCTRL_RST .word 301h
TCTRL_GD .word 3C1h
TCNT .word 0 ; Timer counter value
TPRD .word 0 ; Timer-period value
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LDP Timer0
LD1 @Timer0,AR0 ; Load data page pointer
LD1 0,R0
ST1 R0,*AR0 ; Halt timer
LD1 @TCTRL_RST,R0 ; Configure timer
ST1 R0,*AR0
LD1 @TCNT,R0
ST1 R0,*+AR0(4) ; Load timer counter
LD1 @TPRD,R0
ST1 R0,**+AR0(8) ; Load timer period
LD1 @TCTRL_G0,R0
ST1 R0,*AR0 ; Start timer