Timer Module Example Configuration Code - Motorola MC68340 User Manual

• 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 EQU $0003FF00 Address of SIM40 Module Base Address Reg.
MODBASE EQU $FFFFF000 SIM40 MBAR address value
***************************************************************************
* Timer1 module equates
TIMER1 EQU $600
MCR1 EQU $0
* Timer1 register offsets from timer1 base address
IR1 EQU $604
CR1 EQU $606
SR1 EQU $608
CNTR1 EQU $60A
PRLD11 EQU $60C
COM1 EQU $610
***************************************************************************
***************************************************************************
* Initialize Timer1
***************************************************************************
LEA MODBASE+TIMER1,A0
* Disable timer1
CLR.W CR1(A0)
* Clear the TO, TG, and TC bits
CLR.W SR1(A0)
8-28
Freescale Semiconductor, Inc.
Offset from MBAR for timer1 module regs
MCR for timer1
interrupt register timer1
control register timer1
status register timer1
counter register timer1
preload register 1 timer1
compare register timer1
Pointer to timer1 module
MC68340 USER'S MANUAL
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