Motorola MC68340 User Manual
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MC68340 USER’S MANUAL
MOTOROLA
• Enable the counter prescaler (CPE bit).
• Select the selected clock (CLK bit).
• If the PCLK bit is set, select the POTx bits.
• Select the mode of operation (MODEx bits).
• Select the operation of TOUT (OCx bits).
8.5.2 Timer Module Example Configuration Code
The following code is an example of a configuration sequence for the timer module.
***************************************************************************
* MC68340 basic timer module register initialization example code.
* This code is used to initialize the 68340's internal timer module
* registers, providing basic functions for operation.
* It sets up timer1 for square wave generation.
***************************************************************************
***************************************************************************
* equates
***************************************************************************
MBAR
* MC68340 basic timer module register initialization example code.
* This code is used to initialize the 68340's internal timer module
* registers, providing basic functions for operation.
* It sets up timer1 for square wave generation.
***************************************************************************
***************************************************************************
* equates
***************************************************************************
MBAR
EQU $0003FF00 Address of SIM40 Module Base Address Reg.
MODBASE
EQU $FFFFF000 SIM40 MBAR address value
***************************************************************************
* Timer1 module equates
TIMER1
* Timer1 module equates
TIMER1
EQU $600
Offset from MBAR for timer1 module regs
MCR1
EQU $0
MCR for timer1
* Timer1 register offsets from timer1 base address
IR1
IR1
EQU
$604
interrupt register timer1
CR1
EQU
$606
control register timer1
SR1
EQU
$608
status register timer1
CNTR1
EQU
$60A
counter register timer1
PRLD11
EQU
$60C
preload register 1 timer1
COM1
EQU
$610
compare register timer1
***************************************************************************
***************************************************************************
* Initialize Timer1
***************************************************************************
***************************************************************************
* Initialize Timer1
***************************************************************************
LEA
MODBASE+TIMER1,A0
Pointer to timer1 module
* Disable timer1
CLR.W
CR1(A0)
* Clear the TO, TG, and TC bits
CLR.W
SR1(A0)
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