Motorola MC68340 manual Move.W

#$0334,(A0)

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

*This code is used to initialize the 68340's internal DMA channel

*registers, providing basic functions for operation.

*The code sets up channel 1 for internal request generation

*to perform a memory block initialization for 100 bytes.

***************************************************************************

***************************************************************************

*SIM40 equates

***************************************************************************

MBAR	EQU	$0003FF00	Address of SIM40 Module Base Address Reg.
MODBASE	EQU	$FFFFF000	SIM40 MBAR address value
***************************************************************************
* DMA Channel 1 equates
DMACH1	EQU	$780	Offset from MBAR for channel 1 regs
DMAMCR1	EQU	$0	MCR for channel 1
* Channel 1 register offsets from channel 1 base address
DMAINT1	EQU	$4	interrupt register channel 1
DMACCR1	EQU	$8	control register channel 1
DMACSR1	EQU	$A	status register channel 1
DMAFCR1	EQU	$B	function code register channel 1
DMASAR1	EQU	$C	source address register channel 1
DMADAR1	EQU	$10	destination address register channel 1
DMABTC1	EQU	$14	byte transfer count register channel 1
SARADD	EQU	$6000	source address
DARADD	EQU	$8000	destination address
NUMBYTE	EQU	$64	number of bytes to transfer

***************************************************************************

***************************************************************************

*Initialize DMA Channel 1

***************************************************************************

LEA MODBASE+DMACH1,A0 Pointer to channel 1

*Initialize DMA channel 1 MCR

*Normal Operation, ignore FREEZE, dual-address mode. ISM field at 3. Make

*sure CPU32 SR I2-I0 bits are less than or equal to ISM bits for channel

*startup.Supervisor/user reg. unrestricted, MAID field at 3.

*IARB priority at 4.

MOVE.W

*Clear channel control reg.

*Clear STR (start) bit to prevent the channel from starting a transfer early.

CLR.W DMACCR1(A0)

*Initialize interrupt reg.

*Interrupt priority at 7, interrupt vector at $42.

6- 42MC68340 USER’S MANUALMOTOROLA

For More Information On This Product,

Go to: www.freescale.com