Freescale Semiconductor, Inc.
DMAINT1
EQU $4
interrupt register channel 1
DMACCR1 EQU $8
DMACSR1 EQU $A
DMAFCR1 EQU $B
DMASAR1 EQU $C
DMADAR1 EQU $10
DMABTC1 EQU $14
SARADD
control register channel 1
status register channel 1
function code register channel 1
source address register channel 1
destination address register channel 1
byte transfer count register channel 1
EQU $10000
source address
NUMBYTE EQU $C
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, single-address mode. ISM field at 2. 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 7. IARB priority at 1.
MOVE.W
#$1271,(A0)
* 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.
MOVE.W
#$0742,DMAINT1(A0)
* Initialize channel status reg.
* Clear the DONE, BES, BED, CONF and BRKP bits to allow channel to startup.
MOVE.B
#$7C,DMACSR1(A0)
* Initialize function code reg.
* DMA space, user data space for source.
MOVE.B
#$99,DMAFCR1(A0)
* Initialize source operand address
* Source address is equal to $10000.
MOVE.L
SARADD,DMASAR1(A0)
* Initialize the byte transfer count reg.
* The number of bytes to be transferred is $C or 3 long words
MOVE.L
NUMBYTE,DMABTC1(A0)
* Channel control reg. init. and Start DMA transfers
MOTOROLA
MC68340 USER’S MANUAL
6- 39
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